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Will the Serial Console Ever Die?
simpz writes "Will the serial port as a console connection ever be displaced — especially for devices such as switches, routers, SAN boxes, etc.? In one sense it's a simple connection. But it is the only current port that, in order to use, you need to know about wiring / baud rates / parity, etc. It has non-standard pinouts. And it is becoming too slow to upload firmware to dead devices, as the firmware updates get larger. Also, the serial port is rapidly disappearing from new laptops — which is where you often really need it, in data centers. Centronics, PS/2, and current loop are mostly defunct. Is there any sign on the horizon of a USB console connection?"
I use one just fine with an old WACOM 12" tablet under linux, so while the port may be dead, we can still use serial software and hardware. There's no reason you can't use two $15 converters plus a null modem to run that old DOS-based serial telecom program (ah, telix ... thanks for the memories).
... about a decade ago.
What do you mean 'serial ports are rapidly disappearing..' They're all but gone, aren't they?! :-/
Awk! Pieces of eight. Pieces of eight. Pieces of seven... ERROR: General Protection Fault. [Paroty Error.]
I would think so... It's a good question to ask. Same way with IDE ports on motherboards... I mean does ANYONE ever use a floppy disk anymore?
Most of the newer switches, routers, multiplexers and any other device with a serial port for a terminal interface I've had the pleasure of configuring had a web interface. I'd say that's the direction manufacturers are headed and is the next logical step.
~Mike (Titan_X)
It calls out to you.
The great thing about a serial console is that it doesn't take long to figure it out. And you only need 3 wires to get there.
Another nice thing about it is that it's point-to-point, so you don't have to worry about your signals getting lost.
Heck, you can create a serial interface from discrete components if you're really into fun.
So use your serial console for what it's intended to be used for: emergencies and initial configurations.
Support FSF: Stop thinking with your wallet, and think with your imagination. (cc/non-commercial)
First there are plenty of USB-serial converters, so the lack of old-school DB9 serial ports on laptops is entirely a non-issue.
Also, some devices I see are already offering serial console access over USB, basically simulating I imagine what a USB-serial converter looks like, so if you plug into the device, you get USB-serial console access without the need of converting to serial and then having a serial cable. Also, USB carried serial consoles can operate at higher speeds than traditional rs232 cabling allowed, which should address firmware updates, as well as offering other means, such as USB access to real or simulated filesystems over the same USB port as a multi-device hub.
So the short answer, I see, is that the serial console is not "going away", but rather is slowly migrating to USB.
David Gay
I upload firmware and program various devices at work via USB or TCP/IP - and it is great because the connections are fast. However, when something goes very wrong with the devices, the RS232 port always works. Also, being able to get serial data just by listening to a couple pins is far easier than trying to deal with USB connections/drivers you have no clue about.
When it comes down to it, serial works, its easy and it's a life saver.
The latest-generation Cisco devices are switching to USB for console communications. So it's starting to happen...
Help save the critically endangered Blue Iguana
Floppy isn't IDE. Also, even now a lot of optical drives out there still use IDE.
Consumers have long since stopped using serial cables in favour of USB. The only real place that they still exist is to get a serial console on servers in a datacenter. The OP suggests that it might be replaced by USB here too, but this is where I disagree. For that sort of task, network-based services are becoming more common. Ethernet is cheap and easy to deploy, and not that difficult to implement in hardware. Though there'd be nothing to stop a server manufacturer from just building a serial-to-usb converter into their hardware so you get the traditional serial interfaces but using USB. The serial cable isn't dead yet.
It will never die. It will be around forever. Technicians, thousands of years from now will have to interface with wireless psychic rs232 adapters so as to configure their Cisco hyperdrives.
As an embedded device engineer, I love good old UARTs. They are very small cores to add to an FPGA design, simple to write a driver for, and fast enough for most simple debug applications.
Trying that with a USB core is not an easy prospect. And they arent *that* slow. The free UARTlite IP core from Xilinx can run up to 921,600.. plenty fast for most things embedded...
I mean does ANYONE ever use a floppy disk anymore?
For kicks I just hit Servers Direct, and some, maybe most, of the server still offer the option of a 1.44" drive (presumably plugged into the motherboard). I'd hope these days a big honking server mobo would at least support booting from USB key. Certainly seems like a waste these days to be able to buy an 8U box, 3X redundant power supplies, dual or quad Xeon class CPUs, and they're still wasting space for a damn floppy cable mount on the motherboard.
I'm sure "SlashdotMedia" will improve on all the wonders that Dice Holdings blessed us all with
It will exist as long as it is useful. Right now, people are still finding it useful, therefore it still exists. You still see ISA ports around sometimes.
Qxe4
Com on, give the serial port a break. The future may not be bright, baud I would bet it will still play its port.
I say don't drink and drive, you might spill your drink. Before you get behind the wheel just stop and think.
Let's keep it around forever. You kids are going too fast anyway!
You need to take time to ponder the deeper questions, like in-band or out-of-band?
I work for a small electronics manufacturing company, http://www.westmountainradio.com/
and we make a number of devices that use the serial port. In recent years, we had to start including USB-serial adapters with every device for the very reason mentioned: Many newer computers simply do not have RS232 ports anymore.
The RS232 port is a very convenient way to connect with a number of peripheral devices that don't need much bandwidth. In most cases, 9600 BPS is plenty. You also have the "handshake" lines which can be used to toggle an external device on or off. We use it to drive an LED and an opto-isolator to key a ham radio transmitter, among other things.
As long as there are low-bandwidth, human-interface devices, there will still be SOME use and purpose for the RS232 port.
Willie...
I wonder what was Steve Jobs' reaction when he was told that the Xserve is going to have a serial port, considered "legacy" by Apple since the iMac in 1998.
I still design lots of equipment with serial interfaces inside. It is much easier to connect to a low-end microcontroller which may barely have even a single UART. And even for a higher-end processor, it's so much easier to build the interface. Developing a USB interface requires a pretty detailed understanding of USB - selecting endpoints, which transfer protocol to use, etc - so there's a big software investment and often a significant additional hardware investment to implement a USB interface. Serial is often damn close to free, so easy that it's a no-brainer to put in. And for ethernet devices like switches I can't imagine why anyone would want to bother with a USB interface when you already have 8/16/48 copies of an ethernet interface available, just plop down yet another copy of the ethernet PHY design and make that your console interface.
Point is - serial's EASY to give you, so you're gonna keep getting it for a while.
Just my $0.55 (US inflation, 1774-2008, for $0.02)
I actually posted an Ask-Slashdot about running a headless Linux Box that didn't have any serial ports... my question was about what happened in the 5% of cases where I couldn't SSH to the box (like if a kernel upgrade goes south). The basic answer was that I still needed a serial terminal. Oh, I know that USB can be used as a substitute, but the problem was that USB required a booted & functional kernel with a working USB stack to emulate the serial line. I recently saw a similar discussion in comments about how bad the old-school serial terminal code that is still in the Linux kernel is. Many people incorrectly thought the poster was saying that Linux shouldn't have a command line interface, which was completely wrong. The poster instead raised the (excellent) point that complicated and buggy software emulating long-obsolete device interfaces may not be good for the Kernel (CLI is NOT the same as a terminal interface).
Are there damn good reasons why RS-232 serial ports should be dropped from modern hardware? Hell yes, not the least of which is a 3-15 volt swing signalling protocol is an invitation to fry the low-voltage electronics on modern systems. However, the CONCEPT of having a box that does not require any type of graphics, or even a working network interface, is still very useful. So... what are the better technologies to accomplish the same goal without having to rely on antiquated hardware implementations?
AntiFA: An abbreviation for Anti First Amendment.
Unfortunately yes. In my workplace we still use floppy disks and other legacy devices because other institutions also still use them.
Processes and systems that were setup 20 years ago still exist and when there is a system setup to handle something across an industry, in the example I'm thinking of its banking related, to get that changed across every company, institution and outlet take not only large amount of capital invest in the new hardware and software, but first agreement of the new standard, and then training after everything is done and then usually also changing large amounts of code that have been setup in each company.
Just because we in IT can see better ways to do things, doesn't mean that management can have the foresight to actually implement it and see it through. And usually they have a point, by the time we have everything implemented and up and running, there could/would be a better way of doing it again!
There is no -1 disagree
USB connections can be accidentally knocked lose, RS-232 can't if the screws were tightened properly.
It took me a while to get this ... then I realized you were talking about a different kind of "console" than xbox, nintendo, or playstation.
The RS-232 serial Port means you do not have to download and install drivers. Since there is no USB standard device ( And there could be) the equipment maker has few choices. Write and qualify a USB Driver ( for each OS), put a USB to serial converter chip in and use is drivers, or try to be a HID Device. Adding a USB Logo means USB Group testing of Hardware and software not cheap either.
Or you can drop in an RS-232 Port and let the user Add in a serial port Card or dongle. That is why they are still there.
BTW ASUS still has a comport on some of it Mother boards.
As for the "greater" question, as will Ethernet/Network/Web interfaces ever surpass it - I will contend, the answer is no - or not any time vaugley soon.
I used to own a company that made NAS appliances - back many many years ago. When you had a "plug-and-play" device going onto a network, there were too many things that could go wrong. The question always came up: What happens if I plug the device in, and can't find it on the network? Sort answer was usualy: RMA. We started building a little LCD display console into our devices, which reduced the RMA rate to [near] zero. This wasn't even in cases where it was "our fault" - but even for stupid things, like the DHCP server was down, or address pool was exhausted, etc.
Many years later, weither I am plugging a terminal server, network power bar, switch, router, or even a laser printer onto the network - the same question comes up - what happens if you do eveything right (so you think) and the damn device doesn't show up? Maybe its because some a**hole got in there and set it to some bizarre static IP address - or whatever - how do you recover? You'll always need some sort of direct access in a time of despariation, and BTW, serial is a whole lot cheaper than an LCD display console.
PATA/IDE... whatever, its the same difference. And no, most optical drives out there are now SATA. Got a new computer a couples months ago, and it has a SATA optical. Goto newegg... the SATA drives outnumber PATA almost 3-1. And the majority of motherboards still carry a PATA port of some kind. Maybe they include it because almost all modern CMOS's still only look towards a floppy disk when there is a full system crash... so maybe its for last resort emergency situations with computers???
Yes, unfortunately. Where I work there is a plasma burning table that has no network interface. We have fiber-optic to all of our other machines but for that table the only option is a floppy disc. This is a concern as floppy's become more scarce, as once a disk goes out to the warehouse we do not let it back into the office (they get very dirty very quickly and jam up the office floppy drives).
Computers allow humans to make mistakes at the fastest speeds known, with the possible exception of tequila and handguns
Serial is cheap, simple, works really well, and you can hook up 15+ year old equipment to it with no problem.
Is it slow? Not really, but firmware updates should be through TFTP or HTTP by now anyways for larger files.
Complicated wiring? RX-TX TX-RX, common ground.
Also RS-232 has many brothers and sisters like:
RS-422 (a high-speed system similar to RS-232 but with differential signaling)
RS-423 (a high-speed system similar to RS-422 but with unbalanced signaling)
RS-449 (a functional and mechanical interface that used RS-422 and RS-423 signals - it never caught on like RS-232 and was withdrawn by the EIA)
RS-485 (a descendant of RS-422 that can be used as a bus in multidrop configurations)
On the USB console: yeah, you can have a USB console. Most like there will be a FTDI chip, which will make your USB into a serial connection. Want an example? Arduino.....
By the way, the post is kinda mis-worded.... USB is a serial bus, so a USB console is technically a SERIAL console :)
you can boot and start listening for commands on a serial port without
any ip addresses or netmasks or gateways or any configuration
whatsoever. That's the key.
Not so much in the standard computer world, but in broadcasting for example, many of the automation systems rely on plain old serial connections to fire off various components. How much bandwidth do you really need to send a simple command or two? If you are sending small short packets with byte sizes you can count on your fingers... is USB or TCP really any faster?
Put another way, where space isn't the primary concern, serial is dirt cheap, simple to use and configure, has fewer restrictions on cable length, and wire grade, and is more than adequate for many purposes... If it ain't broke, don't fix it.
That said... once a certain level of complexity is reached, ethernet, USB etc. become much more attractive.
I've never seen an IDE floppy. There are still IDE optical drives around and a lot of surplus IDE hard drives, but floppies were always their own special interface. Hint: vendors now refer to IDE as PATA.
Yes, they filter dust in my desktop machines.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
I work in the offshore survey industry (oil/gas industry), and 95% of products to date still come with serial ports. They are critical for our purposes, and onboard com ports are a must for timing critical jobs such as multibeam bathymetric surveys.
Current project im working on we are using Moxa multiport serial boards w/ 32 serial ports on this pc with around 25 currently inuse for IO. (Historically used Digi boards but they were awful for timing (relatively!), 30ms delay compared to the near 0ms on the Moxa units.)
Simple to use, easily available, and cheap. Almost all the devices I work with use standard parity/stop bits etc, just varying baud rates, which is easy enough to remember.
like a fox..
I attended its funeral yesterday. It was an open-casket ceremony, and people just couldn't seem to resist fingering the deceased. Sadly it didn't respond.
Is there any sign on the horizon of a USB console connection?
There is no standard USB device class for serial adapters. There is communications device class, but it is huge and doesn't really help. So FTDI and Cygnal and others have to write their own drivers for tens of OSes and architectures. If you walk up to a device with a laptop and a USB cable, chances are that your laptop doesn't have a proper driver. To make things worse, many USB-Serial adapters have to use their own VID/PID/REV identifiers, and that makes it even harder to recognize the device. Class-compliant devices would "just work" like a USB drive does, or a mouse.
There is also no standard API in OSes to talk to *modern* serial devices. USB serial devices are emulated into a virtual COM port.
I understand what you are saying: RS232 ports suck for any number of reasons.
But there are a few why it is still often used.
First, it has been ubiquitous for 20 to 30 years. When I started my first development job in 1982 - everything talked to everything else via RS-232. Back then 9600 baud was considered fast. At 8 bits per character with no parity and one stop bit, 9600 baud could paint a screen with characters in one second. Yes, we thought that was fast. Things got better as baud rates improved - but RS-232 remained everywhere - it was the one constant universal interface. Even though it is incredible antiqued, it is still in many PCs.
Second, RS-232 (and its many cousins like RS-422) are very, very easy to use in software. The simplest I/O can be done in a few lines of code. Its easy to put RS-232 code right in firmware. This makes it easy to write bootstrapers, boot consoles, debug consoles etc.
USB would be a poor choice for a replacement. The reason is that it isnt peer to peer - it is a master/slave architecture. There is always one master -usually a PC, and one or more slaves (keyboards, mice, printers, scanners, cable modems, disk drives, storage keys, cameras etc).
It requires a special cable to make to client USB devices talk to each other. This cable has a small do-dad that looks like a master to both ends. This works ok, but it requires special knowledge of this USB end point to work correctly. Note, Windows began to support this in Vista for migration. Its called Windows Easy Transfer/a>.. There is a version for XP too (downloadable/a>). It actually works very well, but the cables were not cheap. Note that the cables really are not cables - but a dual-headed master USB controller with two ports - it just looks like a cable with a lump in the middle - Belkin sells one for $40.
LLike a few other posters have said - USB is much more complex to use in software than simple RS-232. Ive written code for it and I find it more complex than Ethernet at the MAC level.
I think Ethernet is the real replacement. A little TFT or Telnet server / client is really trivial to write. This can (and often has been done) in firmware. For example, most (all?) home Ethernet and wireless routers dont have a serial port. Their management is over Ethernet - works great.
-Foredecker
Jibe!
RS232 rocks,and will always rock.
I actually designed a converter that turns an 9-pin serial port into 6 USB ports plus an ethernet port. Check it out:
http://www.facebook.com/#!/album.php?aid=2022767&id=1462922757
PATA != FDC port. Both still have uses. BIOS recovery is one. The boot block contains a very primitive recovery mechanism for bad flashes. A floppy is one of the easiest devices to code for and FAT12 is a well understood filesystem that is easy for simple code to grep. Unlike floppies, hard drives can contain any number of filesystems all of which are far more complex. Flash devices sound like a great replacement until you realize that USB support must also be included which is almost impossible to fit into the tiny boot block.
there are plenty of PATA devices still out there so having a PATA port on the mobo is very handy. I never understood these zealots who think that merely having a legacy port on their new motherboard somehow contaminates it. If you don't have any devices that use it, shut it off. Who knows, someday you might end up with one.
they need to use SD card / usb keys for firmware / base / fallback config. just put in a small eprom with a base boot code that can reed a usb key to upload the firmware. The SAM system is build like this and is a lot easier to update then burning new eprom for full code updates.
Probably not. Serial is s$#t simple and utterly reliable in dire circumstances. I'm a network engineer at a large university and have spent the last 3 years setting up an "out-of-band" network that includes serial access to all of our network devices. The bit rates can be increased to upload firmware when necessary. Cabling is straightforward and follows the old DTE/DCE standards. The new devices that have USB Type A physical interfaces that I have come across still RS-232 signaling, requiring special cables. We recently had to make a batch of these custom cables to accommodate access to serial ports on new blade chassis SAN equipment. Like it or not, RS-232 serial ports will be around for a good, long while.
I designed a serial to USB/Ethernet adapter so legacy serial ports can upconvert to either standard. Underneath all these other technologies, is and will always be a serial port.
Check it out
I happen to own an IDE floppy drive in the form of an LS-120, and it worked fine last time I used it. Other variations of that drive had SCSI, parallel, or USB interfaces.
My current floppy drive (read: the last one I'll ever buy) is a USB device made by NEC. It, too, just works.
Kid-proof tablet..
RS232 is easy to program. If it's a switch without OS or some other embedded device, RS232 is the easiest and fastest way.
Sure on the PC side there are the problems of baud, parity and so on. Thing is on the device side you can get a working bidi buffered transmission within 30 lines of assembler (100-200 if you have no UART and need to push each bit yourself). Writing equivalent of "hello world" over USB becomes kilobytes. And if you go into a web interface, you quickly lose enthusiasm as you realize on top of CGI you need to write the web server, the TCP stack, the IP stack, and if you're unlucky, the Ethernet protocol stack (in VHDL) as well.
On top of that, a thousand things can go wrong in writing USB or Ethernet or whatever. RS232 is rugged, fault-proof, it works from moment zero. You will be able to communicate with bootloader which has no idea what ethernet is, you will be able to diagnose faults when 90% of essential peripherials are fried, and if the cable goes loose, just move it around a bit and the connection will be back, no timeouts, no disconnects, no "intelligence" to get in your way.
And if you open various devices that use USB instead of serial, you will find a neat little FDDI, Profilic or such chip connected to the USB interface. The devices really connect over RS232. They just have the "RS232 over USB dongle" built in.
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
Floppies STILL aren't IDE/PATA. Ever notice how they use a different pin count (34 vs 40), and are configured in the BIOS separately?
http://en.wikipedia.org/wiki/Floppy_disk_controller
Guess what every SAC box has strapped to the back of the equipment rack - a US Robotics full-size (about 12"x7"x1") Courier modem!
Damned if I know where they're getting them from - but there they are...
Been there, done that, paid for the T-shirt
and didn't get it
If you exclude the TxD and RxD (and Ground) lines, there are still 6 others, which are trivial to interface to. YOu get 4 inputs and 2 outputs, to which you can connect switches and LEDs directly. Then use setserial/statserial to control/monitor the logic levels. This is actually quite useful sometimes.
The great thing about a serial port is it's simplicity from a programming standpoint. Since console access is needed for diagnostics (that is, something is already wrong), the less it depends on, the better.
Most of the problems can be fixed by having vendors not all use different and OH-SO-SPECIAL pinouts for the serial connection and a dirt cheap USB Serial port for the laptop.
I can't recall the last time I saw a serial port that wouldn't accept 9600 8-N-1. Not in a couple of decades.
http://rocknerd.co.uk
With the increasing complexity of network devices - switches, routers, load-balancers, firewalls, the expectancy of a functional terminal console puts a good design constraint on system developers. If they have to provide the ability within a 80x24 terminal funtionality to configure, operate and maintain a such a device it is a good thing. A good management is useful in providing an overview of the configuration and helps provide linkage to the management of components.
A serial terminal console is good because:-
* It enforces the designer to limit the presentation of management information to the 80x24 screen (possibly using pages), and often with a 9600bps data rate. My view is if they can't do it properly in a console they have not though well enough about management. Too often GUIs for management tend to hide important configuration parameters away.
* A terminal console allows easy copy-and-paste and script munging of configurations to ensure consistent deployment. GUIs don't allow such duplication of configurations very well.
* It allows simple out of band management through the use of a terminal server connecting multiple consoles. Such a simple management connection provides am always available management window in a network down situation. (Assuming this is deployed properly). You can also manage the risk well if management can ONLY be done by serial (preventing the management network inadvertently being connected to a production network.
* While standarardisation of the physical port (male or female DB9 or RJ45) and host type (DTE or DCE) and even hardware handshaking is right royal pain. At least it is usual possible to determine it after a minimum number of tries. But essential it is pretty straightforward to implement.
* While a USB connection sounds good, I would only prefer it if it was guaranteed to be a zero driver installation.
...has standard serial console ports, along with a USB port that acts as a built-in USB-to-serial adapter. No serial port on your laptop required. And since most Cisco routers now keep the IOS on a CompactFlash card, you can stick the card in a CF reader on your PC to copy an IOS image to it (the days of doing an IOS upgrade over xmodem on serial are loooooooong gone).
Good point, I forgot the LS-120, and yeah, I use a USB drive if I ever need to read floppies. Mine is a combo floppy/memory card reader.
You young whippersnapers and your newfangled serial consoles.
Back when men were men, this is what a manly console looked like; http://www.columbia.edu/acis/history/360-91-panel.jpg
Ian Ameline
It's not widely known but iPods/iPhone have a serial port on their docking connector.
We buy those all the time for OOB redundancy. 56k US Robotics modems run about $300 now though. Pretty funny as I used to have boxes of the old 28.8 and 33.6 ones from when I shutdown a modem bank that I recycled. Now I get to put in purchase orders for 10 modems at a total of 3k. Always makes me laugh.
the Serial port may died out but im sure Serial will stay with us for a very long time since micros need Serial to be programmed with and ontop of that a lot of things use serial type communications such as SATA(SERIAL ata) USB (universal SERIAL bus) and i think Ethernet would have to use a type of serial communication albeit not the same as traditional serial. really i suppose anything that nots parallel(and my laptop has one of those ports but not RS232 serial?!?) is a type of serial...
epic sig..... ya i got nothing
USB-to-Serial Port adapters are old news, Bluetooth-enabled Serial Port Adapters are the new hotness. The first time I heard about one I thought it was a joke. They're real: no more balancing a laptop inside a half-filled rack or looking for an available crash cart!
I'd hope these days a big honking server mobo would at least support booting from USB key.
Most of them do--but you have to realize that it took Microsoft until 2008 to release a server OS that doesn't require floppies to load RAID drivers.
There's no place like
I work for a company that does medium to large business SAN boxes (dedicated block level RAID storage). We've had serial ports on our storage for a very long time and it will continue that way. It is extremely easy to get a serial port up and running from the firmware/bios for a machine that we can start outputting information to it very early in a boot process. Trying to output this type of boot data to ethernet or USB relies on too many other devices and chips coming online first.
Serial is ease to start up with little overhead and is reliable. There is no real tech out there that can do what serial ports can do for low-level board/firmware interaction.
Its not what it is, its something else.
Wow, I haven't heard that term in a couple decades. I remember (somewhat fuzzily) having to rewire an old PC card that was capable of handling a current loop connection (think it was just a somewhat flexible RS232 card from IBM), back in the 8086 days when the pins on a lot of chips were still far enough apart so you could use a soldering pencil on them without trouble. We had an old mass spectrometer that used a current loop interface, except against spec it expected all the voltage/current/whatever to be supplied from the other end for both the transmit and receive loops. We had been using an HP 1000 to control the mass spec for at least a decade, but with the maintenance running about $500/month we really wanted to switch over to a PC. So I ran a wire from the 5V (I think; hey it's been a while) pin on the PC backplane and fed that over an unused line in the serial cable, then at the other end modified the circuit in a way that certainly worked but would probably make any first year EE student either laugh or cry.
Funny thing is, even back then current loop was considered to be dying, and I had a dickens of a time finding any info about it (versus "standard" serial) - but I guess Netcraft hasn't confirmed its death yet so it still hangs on, lingering...
#DeleteChrome
...maybe from USR?
http://www.usr.com/products/modem/business-product.asp?sku=USR3453c
Hell, 386 chips only went out of production in 2007. Home computers do not represent the full industry. Maybe we should do a thread of Tech You Thought Was Dead.
We got a new Sun T5120 Niagara box the other week. New build server. (32 threads in 4 cores, yeah we bought the little one.) Initial setup procedure *requires* serial to the service processor. The IT guy was already upset enough that the KVM he'd arranged had no use on a SPARC box and had to grovel around for a USB serial adapter.
Serial is all-but-dead in desktop PC land and deader than it should be in server PC land. (Sun x86 servers always have serial.) Everything else, serial is standard and thank fuck. RS232 9600 8-N-1, usually to an RJ-45 rather than DB-9 these days. But it remains standard and indispensable. The more back doors you have into your own server, the happier you are when shit breaks.
http://rocknerd.co.uk
http://www.cisco.com/en/US/prod/collateral/routers/ps10538/data_sheet_c78_556319.html says: " A new, innovative, mini-B USB console port supports management connectivity when traditional serial ports are not available. The traditional console and auxiliary ports are also available. Either the USB-based console or the RJ-45-based console port can be used to configure the router."
think Ethernet is the real replacement. A little TFT or Telnet server / client is really trivial to write. This can (and often has been done) in firmware. For example, most (all?) home Ethernet and wireless routers dont have a serial port. Their management is over Ethernet - works great.
This is all well and good provided you have a functioning IP stack, if you don't you may as well just throw the thing in the trash. How many software layers does it take to make that mini web server work?
I can plug ANY Cisco router into a serial port, launch one of a dozen terminal programs and I can actually see the boot loader starting the system up. THAT is valuable functionality.
Hey KID! Yeah you, get the fuck off my lawn!
Many people think it's only 2 wires (TX / RX) comunication. Well you are deadly wrong, you can see in http://en.wikipedia.org/wiki/Serial_port have a lot of other signal and the problem is many "serial usb" conversor are not working properly. I'm having nightmare trying to conect some "not so old" devices with serial port through this "serial-usb" conversor, many simple don't work.
The true is the comunication with serial port is a mess. You don't know if you are receiving or transmiting correctly unless you "alredy" know what you will receive and can check the integrety by youself or the data your sending to device is correct. You even don't know if there are anything conected in serial port. Bottom line, there is no standard for reliable comunication.
Yes, It's easy to develop to serial, very cheap to construct devices with serial port and (for embedded) is very low power consumption, but I think is time to let go this type of device.
They all need to be connected to terminal servers so people can REALLY provide remote support, instead of thinking you can do everything with Telnet...Or RSH...Or SSH...
You can get floppy drives with usb connectors, you know. It's not like you're going to fill up the bandwidth.
Just keep a few old 486 notebooks around with the DB-9 serial ports, and with Win95 and Hyperterm or Kermit (maybe even just FreeDOS and MSDOS Kermit?). Pick up spares whenever someone wants to throw them out as worthless. I used a Compaq Contura 4/33C, a "netbook" before its time from about 15 years ago, with a 486/33 SX, 12 MB RAM, 250 MB HDD (right "Mega", not "Giga"), Win95 and Kermit to manage a number of Sun Servers about 8 years ago when we did patching or trouble shooting. I still use it occasionally for messing with my Ultra60 and Ultra80 at home.
Heck, at times I even used/use a Sharp Zaurus 3500 clamshell PDA ( NOT the Linux types - 1MB RAM, no disk, flash, or any other storage, runs on several AA batteries) with its built-in termulator when I just wanted to do some quick work, and take that in a belt holster to keep my load light for the trek to the server farm. Simple is good.
RO
At my last IT job, we had a serial-to-telnet converter/concentrator, with 20 or 24 RJ-45 serial ports. We also had ~30 headless systems, of all stripes: IBM Power, HP PA-RISC 6U rack-mounts, and lots of Sparcs and PC's. Only LILO or GRUB on the PC's needed to be configured post-install to talk to the serial port; the others were already set up to talk to the serial port, either by default or as a fall-back if the keyboard was detached. Add to that a telnet-enabled power strip, and it was a remote developer's dream.
The big advantage the serial concentrator gave us was being able to reboot and recover from a kernel panic, by being able to manipulate kernel command lines. In the event of a corrupt filesystem, if the fsck program couldn't repair it automatically during boot, the serial console made it possible to attempt a repair remotely. Not having that ability would have severely hampered our development ability.
I have even (very, very carefully) typed serial console parameters into a Linux boot command in SYSLINUX, blindly, and done a Slackware install through a serial console. It took a few tries to get it right, but it saved moving my only monitor, which let me continue working on my desktop system while the install ran.
Well, okay, there was also the "because I can" aspect to it...
Serial may be dead on the PC. But besides routers and switches, there are thousands of other industrial devices that still use the serial port. At my work place, we have weigh scale indicators that use the serial port, and we even have motor controllers that still use ISA bus cards. We looked into replacing those motor controllers, and the replacements use the *parallel port*, another dead port.
I have a ThinkPad with the Ultrabay serial/parallel port adapter. No one's gonna care to pry it from my hands, but I'm keeping it anyway.
While console access via serial port has long been a given on commercial Unix and network hardware, it never caught on in the PC world. Sure, there are specific manufacturers and replacement BIOS options available to allow low level configuration of a PC via the serial port but this should have been standard from the '80s. I truly don't understand why PC manufacturers never saw the value in being able to view boot messages and configure BIOS options via the good ol' serial port.
Break is over!
Back to the salt mines!
Never answer an anonymous letter. - Yogi Berra
When configuring a server (regardless of brand) remotely, what do you do if you really muck up the ports or routes? What if you muck up the management port, too? (I've done this too many times for comfort.) There needs to be an ohshit access method. It needs to be as simple, reliable, and cheap as possible. Serial over rs232 is exquisitely simple, amazingly reliable, and at under $10 a port (server hardware, ditto for a serial switch if you want every box available all the time) it's cheap as heck.
Also, from the server room point of view, one should *never* send updates (software, firmware, FPGA, doesn't matter) over serial. The serial port is there as a last-ditch, nothing-else-is-working connection. It is essentially infallible, and it's what you use to get the management port working again.
So will it go away? Very doubtful. And I would expect the same for every other industrial scenario.
Outside of Real Serious Stuff(if your job involves oil rigs, SCADA, legacy devices that Google has never heard of this probably means you), I strongly suspect that "serial" in the sense of "DE-9 or DB-25 connector that won't freak out when exposed to the full +/- 12(or even a touch more in some cases) volts that serial used when men were men and cable runs were long" is not so long for this world, outside of a few legacy niches.
On the other hand, "serial" in the sense of "a few pins carrying something that looks like rs-232 at whatever voltage this device's logic runs at" or "device has a USB connector; but that just means that they slapped an FTDI or Prolific chip on a serial design" will be more or less immortal. Even in high volume consumer devices, where it isn't supposed to be user accessible, you can generally find a logic-level serial connection somewhere, though it may not be labeled or have any sort of connector soldered in. It costs almost nothing and can save you from having to JTAG your way out of (most) of your mistakes. When designed to be accessible, it is ideal for dealing with initial configuration for devices that communicate primarily over ethernet.
The new Cisco 2900 and 3900 series routers, while still sporting the traditional console port, have a mini-USB port as their primary console connection now. In fact, they don't ship those classic blue rollover cables anymore with the routers.
The times are a changin', my friends.
Cisco has been adding USB to new supervisors, some units they say they are "for furture use" so i'm not sure if USB today can replace Serial, but some units are getting the physical port today...
So i guess it's not too crazy to think that someday. But yes, I don't enjoy hunting for a laptop that still has serial. (usb2serial is not ideal as built int)
Those who can, do.
My current floppy drive (read: the last one I'll ever buy) is a USB device made by NEC. It, too, just works.
I have one made from Samsung. When you say it "just works", though, that's not technically true. As far as I'm aware, USB floppy drives aren't capable of running low-level floppy commands. That means you can't do a low-level format (but you can do a high-level format), so you can't play around with odd track/sector layouts. Not that many people actually want to anymore. Still, I was disappointed when I found out that my fancy, new USB floppy drive was actually less capable than my old, clunky desktop floppy. *sigh*
Not much really - it only takes a very minimal stack to do simple things like TFTP or Telnet. Back in the mid 90's We used do to do this on '186 class stems in a few k of code. Its also easy to do a very simple low level UDP based thing - that that would be a bit proprietary.
I agree that serial ports are useful. What I'm suggesting is that the best alternative is Ethernet, not USB.
Jibe!
PATA/IDE... whatever, its the same difference.
Yes, but they aren't normally floppy connectors.
And no, most optical drives out there are now SATA. Got a new computer a couples months ago, and it has a SATA optical. Goto newegg... the SATA drives outnumber PATA almost 3-1.
And that has nothing to do with units 'out there.' That's new gear. Take a tour in the trenches and you'll still see a lot of machines with IDE optical drives.
...You mean it's not already dead?
I'm honest enough to admit I lie to myself.
If your serial console is 5 meters (16.4 feet) away, or less, USB is fine. 5 meters is the stated maximum cable length for USB. Any longer, and you'll have timing issues. RS232 has a stated maximum cable length of 50 feet at 19200 bps. As another commenter stated, 9600 bps would be quite fast enough, so you can go up to 500 feet. Just make sure you use good cables that effectively shield out both external and internal noise.
For longer distances or noise concerns, like in a manufacturing plant, you can use fiberoptic cable with converters on either end. RS232-to-fiber converters have been around for years, and USB-to-fiber converters are available, too.
As an aside, years ago we upgraded our servers from ones that only had a serial console terminal to ones that had both serial and ethernet based ones. I had no problem going to the ethernet ones, but my boss at the time got nervous. She made me hook up one of the console terminals from our old servers to the new ones. Unfortunately, we had already removed the desk we used in the server room for the console terminals to make room for other servers. I had to put it on one of those movable computer desks and I never could find a good spot for it. Eventually, I went from ops to development, so it became someone else's problem.
It's a very dark ride.
First, it has been ubiquitous for 20 to 30 years.
Hell, longer than that. Not all that long ago I had to interface to a piece of gear made in the late 1960's (a big industrial-strength plotter, basically) Wasn't a problem since it had good ol' rs-232. IIRC, it had a pretty weird parity/stop-bit combo (it used something like 150 7E2) but nothing that a modern UART couldn't handle.
The first teletypes using RS-232 appeared almost 50 (!) years ago now and it was pretty ubiquitous by 40 years ago. Its longevity is incredible. I hope it keeps its niche, it's still very handy.
many server-class motherboards still require IDE optical drives, and with some chipsets an optical drive can't be used on SATA because the SATA RAID chipset is only for hard drives, unless you switch them to JBOD/IDE/AHCI mode rather than RAID. Now, I'll give you that in an ideal world one would be using a hardware RAID controller (SAS or SATA, anything but fakeRAID) but the reality is that bean counters often won't pay the small premium for that upgrade.
IDE should die but it's going to be around for a while longer.
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
Anyone who has to support Windows 2003 or XP or earlier uses floppy drives on a regular basis.
Fortunately, most servers will work with a USB floppy drive just fine. Not all will though.
Also, many server BIOS update routines require booting off the floppy drive - You can often work around that but it's a pain in the neck - it's easier just to have a floppy drive installed in the server even though you'll use it two or three times during the life of the server.
The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
Servers probably still use floppy drives because there is still no viable floppy replacement.
Yes, I do use a floppy: my home router is running from a write-protected floppy disk. I am not sure if I can keep using a floppy disk in the transition to IPv6. The 2.6.x Linux kernel doesn't really fit on a floppy disk.
Just to make sure it is understood. There is no relationship between USB and RS-232 or RS-422/455 but the term "serial" on its name. RS-232 is not to be replaced any soon since it is simple, solid, easy and do not fails for what it is meant to be used. There is no replacement for it yet. USB is good at what it is, but it is not good at replacing RS-232. It is like plane replacing bicycles. Both are transports, similarities ends there. RS-232 will be left when ethernet interfaces get so interoperables that a single driver will be needed. Do not hold your breath for it. Even now some devices are setup using broadcast and carefully crafted packets. Would be nice to know that IPv6 has reserved a network for that, but I do not think that something so usefull is to be done.
From a device manufacturer's point of view, RS232 is free to implement. No special drivers are required on the host.
Now, for USB, you have to either pony up $2000 PER YEAR to the USB implementers forum to get your own VID/PID and distribute a driver to your customers (and deal with the resulting customer service issues) or add a chip from FTDI (or similar) and piggyback on their VID/PID but then ask your customers to download and install a generic driver that does not specifically identify your hardware.
Gimme RS232 any day.
Buy new stuff.
6.8SPC TR of 550, l xwind at 6, drift rt at 26" drops 77". AT has 503 ft-lbs at 1403 fps. FT 0.86
serial consoles for unix / linux servers will continue as long as vendors ship their servers/blades with lame java based video console extenders and terrible buggy ssh implementations. The latest IBM system X 'imm' implementations still suck because of complex architectures like Java WebStart that dont play well with the firewalls that NAT which are almost always in between the sysadmins workstation and the servers to be administered. sun x86 and HP servers are not much better. at least with sun sparc gear the openboot implementations are very stable now, and hardly anyone contemplates running serial to these much any more. but the future of x86/x64 architectures still seems bound up in video consoles, or 'serial redirect' where the bios setup gets turned into curses style serial.. sorta. ie its all hacks and kludges.
Who wants to be known as a serial killer?
Have gnu, will travel.
take your pick.
Don't forget USB kernel debugging support in Vista too. It uses a Net20DC.
I'd hope these days a big honking server mobo would at least support booting from USB key.
Most of them do--but you have to realize that it took Microsoft until 2008 to release a server OS that doesn't require floppies to load RAID drivers.
Then again, it's hard to take anyone seriously that uses Windows in a server role.
Game! - Where the stick is mightier than the sword!
I still have my Courier V.everything modem from the 90's.. Was upgradeable for every change up until the v.92 standard, and was the best modem available through v.90.
I don't even have a landline at home anymore, but still can't bring my self to get rid such a long-lived piece of tech...
Also, security tip: Wardialing isn't dead, it's just gotten better.. Modems are an oft overlooked piece of a security strategy, and it's still fun to get to p0wn a company through some old 33.6K modem on an audit..
Blessed are the pessimists, for they have made backups.
Yep, remember the age of minicomputers? PDP-11, VAX, Data General, etc?
I bought my work laptop, a Dell E6400 ATG (semi-ruggedized) with the Dell Legacy Extender. It locks into the docking station port on the bottom of the rig and has a real UART chip inside attached to the system bus making it a real RS232 serial port. I program industrial robotics and have yet to find an instance where it does not work. Some of the systems I connect to are 20+ years old.
I Don't Work Here
1. RS-232 hardware connectivity.
2. VT-52 or more command line.
Well, I have a current loop device on my desk. I had to design and build a USB to current loop converter for a 60mA 120VDC current loop.
But that, of course, is a retro technology tour de force.
> USB keys don't have write-protect tabs, so you have to be careful plugging into a compromised box.
Many microSD (or microSDHC) cards come with an SD card adapter and some of the adapters still have a write-protect switch. You can then plug that adapter into a small USB card reader, and voilà! Possible to still have "USB key" with write-protect.
You also should still be able to find 2GiB SD cards which have write-protect switches which can be used directly in the same card readers (and last time I checked, the 2.6 kernel wasn't that bloated <wink>).
Not all hardware has to be thrown into garbage just because it's old.
This machine has 11 UARTs on it, 4 of them are RS-422, the rest are normal 232.
I've got a couple 232 lines to other puters in this room, and a router.
RS-422 goes down to the basement, and controls the machines down there, ethernet or not.
There is a getty running on one, in case I get too drunk and smash the monitor.
I use the remainder for connecting to my microcontroller projects and programmers, etc.
You can run it on *ancient* hardware, with no resources. It's incredibly useful for debugging microcontroller programs.
Things that only have 128bytes of RAM, and a few k of program rom...
You can hook it up to a 40 year old TTY and it will work.
You can haul a dumb terminal out from a cave and it will work.
You can short every pin of the serial port together, leave it there for a decade, come back, and the bloody thing will still work.
I'm a rather miserable programmer, and serial is a bloody cakewalk to interface to. USB, on the other hand, isn't quite as simple.
And it's a *standard*. Man I love things that are standardized.
Sent from my PDP-11
SuperDisk... same foot print as a floppy, also read floppys, and was IDE
http://en.wikipedia.org/wiki/SuperDisk
Are you sure? I seem to recall using it to make some OS/2 install floppies a few years ago, which (IIRC) have a non-standard format.
Kid-proof tablet..
Damned if I know where they're getting them from - but there they are...
They still sell them[1]. No matter how much engineering goes into USB or the TCP/IP stack, they're still more prone to failure than 56k modems and a serial port.
[1] http://www.usr.com/products/modem/business-product.asp?sku=USR3453c
That works pretty well when the device is supposed to be a DHCP server to begin with, but not so much, otherwise.
How do you configure the IP address of a new device? With, say, printers, there's some proprietary software that will scan the entire network for BrandX devices and offer a GUI to configure them. And then any network protocol is pretty impractical for the simple reason that you get disconnected upon device reboots, and no way to know to auto-reconnect upon restart. Compare this to RS-232, where it's as simple as walking over and plugging-in to the device directly, and having a continuous connection as good as if you had a keyboard and monitor wired-up.
These issues make it very cumbersome and clumsy in enough ways that it won't catch on in the business-space as it currently is. A whole new protocol is needed for this kind of device management over ethernet... and good luck implementing all this in a PC BIOS...
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Why all this stone age stuff when you can have TCP/IP over ethernet with technologies like iLO, LOM and the likes running on separate integrated hardware?
Stop thinking in terms of interfaces, please, and start worrying about services!
Maybe Computers will never be as intelligent as Humans.
For sure they won't ever become so stupid. [VR-1988]
"Software is getting slower more rapidly than hardware becomes faster." -Wirth
Lets see - I'm building a UAV using RS-422 for fly-by-wire operation using a RTOS and embedded hardware. Do I want TCP/IP or USB buffers involved on servos that control its ability to stay in the air? I can only imagine getting a lecture from an engineer at Raytheon about keeping things simple.
I wonder if someone will make a joke about selling Toyota Motor Corp a USB accelerator control...
The first is obviously that it's really easy to implement on microcontrollers. Plus it always works.
The second problem is less obvious. Have you ever tried to use one of those USB->Serial converters under Windows? In every other OS you just plug them in and they work. This is because they are part of the USB standard. With Windows you need a driver for each one of them. So if you want to save your bricked router over USB, you'd first have to find the CD-Rom with the driver for that particular USB->Serial converter. Good luck with that.
Back when men were men, this is what a manly console looked like; http://www.columbia.edu/acis/history/360-91-panel.jpg
The younguns should note the suit and tie. It was how we got things done. That's right. Getting things done required a Real Man wearing a Real Suit And Tie. Or labcoat and tie.
"For example, most (all?) home Ethernet and wireless routers dont have a serial port. "
I strongly disagree with that! EVERY processor used in wireless routers do have serial or at least JTAG port. Thankfully, because when you brick them, that is the only way out.
I work in networking and the console port a must for out-of-band recovery and initial setup.
What really iritates me is the removal of console ports on laptops. My works laptop has a console port, because we are careful about rthe correct box (my next laptop will not have a console port due to changes in the company).
Solution - All laptops have a modem port, but increasingly no console - now why can't the modem port be made to switch to pure serial RS232 signalling for people like me who never use the modem but use serial consoles every day.
Then you could get a RJ11 to db9 to give you a proper serial port. So that RJ11 port for the modem could server two functions and without having the large DB9 using up laptop port real estate.
Just my thoughts
First of all, it's important to distinguish that RS-232 is just a signalling convention. RS-232 requires an RS-232 transceiver, exactly the same way that USB requires a USB transceiver. Both of these technologies are for serial communication. Both of these technologies can be backed by a UART (see Catsoulis) but USB often skips the UART backend, opting for direct access instead. What you're really talking about is replacing the traditional RS-232 transceiver with a USB transceiver on devices. Sure, why not?
Reason 1) a UART is absolutely crucial for OS debugging, boot loader debugging, and recovery from corrupt nand, because it's cheap, simple, and sufficient. Often (especially when reverse engineering a device) a UART can be the only way to interact with the OS during the porting phase.
Reason 2) Although most (decent) OS have a USB stack that will work in both host and device mode simultaneously, often there is some external hardware preventing direct usage of an OTG or USB-device port (e.g. VBUS sensing). Interfacing with a UART requires no knowledge of external circuitry aside from pin configuration.
Reason 3) Lower-level 'operating systems' that run on microcontrollers or DSP often do not have such a sophisticated USB stack. UARTs are just simpler.
So now that we know complete replacement is unlikely... I can tell you that the USB console you're asking for is already here (with varying protocols). The protocol is determined by the device in question (either statically or at runtime) and will typically be one of i) CDC Ethernet / RNDIS, or ii) CDC Modem, but custom protocols are also possible.
CDC Ethernet is essentially what you're looking for in terms of 'auto-negotiating' baud rates, but you still need to configure the Ethernet / IP layers. Drivers exist for most decent host operating systems, and even Windows!
The device in question needs to have an OTG or USB-device port, neither of which you're likely to see on x86 or x86_64 chips without external hardware (AFAIK manufacturers assume that x86 chips are always the host in a USB transaction). On the other hand, most ARM SoC have had an OTG or USB-device port for years already.
Are there damn good reasons why RS-232 serial ports should be dropped from modern hardware? Hell yes, not the least of which is a 3-15 volt swing signalling protocol is an invitation to fry the low-voltage electronics on modern systems.
A lot of current embedded hardware has a serial connection with TTL levels. It may be for debugging/hacking only on the PCB, for example on my Nokia N800 and Buffalo Linkstation Live. On the other hand, some older equipment uses TTL level serial as the main outside connection, for example my old Nokia 6110 phone and my Casio graphing calculator. I guess the reason is not so much the fear of frying sensitive electronics, but the extra hardware needed to generate the higher voltages.
Escher was the first MC and Giger invented the HR department.
Serial is a digital, bit-accurate protocol that has been phased out for a long time. On the other hand, we still have the analog blur of VGA as the only external display connection on many current computers.
http://iki.fi/teknohog/rants/vga.php
Escher was the first MC and Giger invented the HR department.
People who configure routers, switches and other RS232 equipped things do usually know those funny baud rate, parity, stop bit etc. things.
Btw. you may run an RS232 at a megabit or more, that is what UMTS adapters usually do, even when you connect them as USB or PCCARD devices.
Limits are only in BIOS, you may run is as fast as it is technically possible which is a lot more than the usual max of [insert preferred max. speed here]. The reason for not doing it is to be compatible with older hardware.
Try getting U-Boot (http://en.wikipedia.org/wiki/Das_U-Boot) to work without one.
Or early Linux embedded board bring-up.
Or virtually any microcontroller work, where all but the simplest of devices have one or more UARTs.
Go on, prise my serial port from my cold dead fingers...
Serial is standard, whereas USB devices typically need drivers...
The Marvell Sheevaplug for instance has a USB console port, but you need to install drivers... Linux has these drivers by default, but osx/windows don't, and the osx drivers are horrendously buggy.
http://spamdecoy.net - free throwaway anonymous email - avoid spam!
Properly secured business workstations and servers have USB (and FW) disabled. Add to that huge investment in PS/2 based KVM switches and no, PS/2 is not "mostly defunct".
I've had a linux box go totally Helen Keller - X stuck, not responding to keyboard or mouse, couldn't get in with SSH over the network.
I was able to get in with my Psion 5 via the serial port and perform an orderly restart.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Everybody saying just use USB are having a little bit of tunnel vision for YOUR use of serial/usb.
you are envisioning a laptop in hand and walking up to a device, close enough that a USB cable is an option.
It is not always that way.
I've personally run serial cables hundreds of feet to machine tools from a central code storage computer.
Now try that with a USB cable. you have to have a powered hub every, what, 6 or 8 feet for a 250 foot run?
Not all serial connections are Rs-232, some have longer transmission lengths, and by slowing the baud rate, up to 4000 ft (from wikipedia).
Serial does things USB does not, so it won't be replaced till something does everything it does, and better.
It is just not USB at this point.
More realible than USB (EMC).
Serial connectors are a lot more reliable than those modular things used for ethernet.
RS232 still makes sense.
I'd be very surprised if it was otherwise. Simpler generally means more reliable.
...all use SERIAL, even today.
Unfortunately all my new PC's only come with USB, so I'm using older computers to be compatible with both the SOFTWARE (that wasn't made for seriously fast computers) and the RS232. ;)
I'm using a 3 dollar USB-to-Serial on my newer pc's though. (China, yay!)
I have a whole bunch of RS232 based stuff, my two Eprom burners all use RS232, my 8x52 series MCU devboards (purchased recently!) use RS232...My Roland compatible XY flatbed plotter (used to plot PCBs) uses it... ...so no - it ain't going anytime soon.
My Radio-Amateur modem (Multi modem), connected to my radio-amateur gear...also uses it...and the list is virtually ENDLESS
What this world is coming to - is for you and me to decide.
Even your "three wire description" has left something important out, that I've seen mis-wired: the third wire is _signal ground_, not "common ground". "Common ground" is when we share something interesting to talk about: it's an unfortunate choice of words for wiring.
What's a better term for the "signal ground" that is "common" to all signals?
Why should it, if it 'aint broken, don't fix it!
Yes, quite recently in fact. There's still plenty of hardware around that needs a floppy for firmware upgrades.
Now, if the FireWire S800T with Ethernet cabling would be royalty free standard...
The two I bought were only $11.14 each and worked in Ubuntu 9.10. I haven't tried BSD or Windows, yet. Well, OK, there is also shipping.
now we need to go OSS in diesel cars
I think the DB-9 connector is a little big for what its doing though, I mean even a DB-15 monitor type connector is duplo size for 15 pins.
Maybe I just like Cisco to much, but it would be nice to have everyone just use the Cisco RJ-45 spec for serial connections, I hate when other router/switch vendors use RJ45 but the pins-outs are totally different so you have to find that special DB9 to RJ45 adapter for that 1 piece of gear, instead of using 1 of the Cisco adapters that you have laying everywhere.
Even if on the back of laptops they used RJ45 for serial and marked they would keep it around longer? the DB9 connector seems to big realistate wise to me I guess.
Then you could just use a regular RJ45 cable to connect between the 2, no need for some non-standard cable.
Also for those of you that use console servers allot, I still think the older Cisco access servers that many use for console servers now a days are better than any of the Linux server type solutions I have tried. The Cisco access devices supports telnet to each port, a real routing table that supports multiple gateways via static or even routing protocols like OSPF etc... also Tacacs+ auth if you need that.
For anyone in the unix world, this is a ridiculous question. Serial ain't goin' nowhere, thank Xenu. Actually, MacOSX + screen + generic USB serial dongle works darn well for consoling into host serials..
For Windows folks, I can understand the curiosity.
Serial is the ASCII of communications links.
I have to say it right up front. I love serial ports. They are simple to implement in hardware and software. The are simple to use. They are easy to understand. While I'd say that the Maxim chips have made RS232 easier to implement, you can still wire your own without it. Of course, it's possible to do the same with USB, but it would take quite a bit more work and it wouldn't be a "legal" USB port without joining the association.
There's no denying that USB has a faster transfer rate than any RS232 implementations that I've seen. But, that's not always necessary and any time that I see where you have to join a group to implement something (hardware, software, etc.) I automatically think that the group is trying corner the market on something. (Maybe I'm cynical?) USB really is contrary to the freedoms that we've come to enjoy in open source software and I sometimes find that distasteful. It's also made it easier for the large corporations to implement (properly) than the smaller companies. Is it a necessary evil at this point? Maybe. Is it the right solution for some things? At this point, certainly. That doesn't mean that I should have to use it for everything. And... given the choice, I'd rather see a simple serial port with USB speed that you don't have to spend 100s of man hours and/or sell (a part of) your soul to implement.
And some vendors still release their firmware updates as floppy images... Even worse when they come as a windows program, which when executed writes the image to a floppy (ie you don't just have the raw image file which you could dd on linux or load into the virtual floppy feature in most lights out management firmware).
http://spamdecoy.net - free throwaway anonymous email - avoid spam!
Why would you use NAT in your internal management networks?
I call BS, ever since Windows 2000 you have been able to add drivers for a disk controller to a cd. Here are the details: http://support.microsoft.com/kb/314479 or for the lazy man check out http://www.nliteos.com/.
How do you configure the IP address of a new device?
DHCP, with easy fallback to link-local addresses. Once you've created a static connection, DHCP will no longer be used. Or if you use DHCP correctly, you get the MAC off the device (usually on a sticker) and give it a DHCP configuration before you even plug it in. That way you can change the address by editing the DHCP config, and rebooting the device. HTH, HAND.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Serial ports are cheap and easy to interface to, both from hardware and firmware perspectives.
- a simple MAX3232 chip, four 0.1uF caps and you're done
- read/write a byte every interrupt
- messed up pinout doesn't harm the driver, just try again
- three wire interface, symmetric
USB requires more hardware, and a protocol stack (which you might have to pay for)
- not all micros have room (or MIPS) for a USB stack
- impedance control needed on the pair
- host or device - you must choose or use OTG if supported on the micro
I'll admit USB is faster and has more capability, but a small, low power embedded system might not be able to support USB, while it can handle serial just fine.
*That's* why serial will never go away.
I am the IT director for a medical device company - we make software that runs on laptops which connected to physiological monitors, and the way these connect is via a serial port. I procure the laptops, etc and this has been a major problem since the DB ports started being phased out around 2005 or so.
Serial ports have disappeared from almost all consumer laptops; basically any laptop made for anything other than business or utilitarian use no longer has one.
Models which do have serial ports still are Panasonic Toughbooks, one model of Dell Latitude, and HP and Toshiba both have at least one model. (these are the ones I know about).
USB to serial (DB9) adaptors are convenient and nice and all that, but when things like timing matter they are not reliable - so for things like military and medical applications, they aren't a good way to go.
As far as USB to Serial adaptors go, we've tried all of them, and in my opinion, when it comes to proper timing and reliable usage, the Belkins are the best.
Most discussions are talking about USB to serial adapters of one sort or another.
While I appreciate the discussion, the question of the article is whether or not new devices that use serial ports for their console should move on to something else. I think they should. We flipped out when people spoke of ditching the floppy. PS/2 ports disappeared without much discussion or complaint. And as for printer ports? I barely noticed that they disappeared, but now that you mention it, they are mostly gone too. (Most of my printers are connected using the network port.) But once again, I find myself talking more about the PC side of things rather than the devices we seek to access or control.
Frankly, console ports should either be network or USB ports and I favor network ports. While the complexity of a web console would make them more expensive, things are still evolving and make them less expensive. Web consoles can be accessed by any number of devices and made to work in any number of ways not the least of which is remotely from very long distances. (This also brings about security concerns, I know... that's another discussion.) USB suffers from the same problem that serial suffers -- its capacity for distance (length of cable) and the requirement of physical access. Some would argue those are a plus when it comes to security (once again, another discussion) but for all other concerns, USB is lacking and frankly, while USB is a great carrier bus, it doesn't have particular protocols implied to it that ethernet does.
What do I mean by that? Well, while ethernet can carry a wide range of protocols over its wires (just as USB can) lately, nearly all other protocols have falled out of favor or completely from view. Does anyone use Netbeui? IPX? Banyan VINES? Essentially, ethernet says "TCP/IP" these days and all of the stuff it involves from telnet to http. If a console standard were to be issued, it should be using ethernet and http as the interface to the user. Telnet would be more simple in many respects, but http is a much more available client protocol.
With USB, on the other hand, you pretty much have to decide on what will be emulated over USB before anything useful in the way of a console could be developed. Would we be emulating a serial port? A network link? What sort of user interface would we use when accessing the consoles of these devices? There is CLI and GUI. What else is there? In any case, the emulation of whatever would likely require drivers of some sort or another. The USB to serial and serial to USB chips out there would make plugging into a device with USB show a new serial port connected to the PC. That's easy enough, I suppose, but do we really want to add and remove entire devices to our kernels when connecting and disconnecting?
The latest series of branch routers from Cisco, the ISR G2, includes both a traditional serial and new-fangled USB console port. Essentially it's just moving the USB-to-Serial chip inside the router, but it does eliminate one potential thing you can lose or forget. They're going to be including both option on several new devices in the future but it's going to take a really really long time for serial to completely go away.
I work for a company that builds essentially really smart terminal servers, and we still highly favor serial console ports. You can dial into our device and still access all your devices via the console port. Which is pretty important when you consider that one of the most common reasons a network is unavailable is a misconfigured router (so getting onto the network isn't always that helpful).
I think that keeping the console port and having a usb port where you can attach a thumb drive to upload the os via flash if necessary is probably the best route. USB/Serial is not particularly reliable in our experience.
There is actualy an old protocol (Cannot find the RFC) for ad hoc IP address assgiment. There is also universal plug and play. Both would work just fine here. Two devices could also simply communite with a simple protocol righ ton top of the MAC layer. Like many other things, people were doing this stuff 15 years ago.
Jibe!
When it comes to USB there is the DFU (Device Firmware Update) class, but Apple and Microsoft do not include DFU drivers with their OS's. Even though DFU is a standard class, there are no decent commercially available DFU drivers out there. Atmel has a series of micros that have USB built in to the micro and DFU included in their application framework, but they use the open-source libusb drivers for updating firmware on their chips. I write installers for software that updates commercially available embedded systems. We currently use FTDI USB to serial chips in most of our devices.. Driver installation is one of our biggest support hassles. Every time a new version of an OS comes out, it is a scramble to make sure we support it. However, FTDI provide drivers for free, so I can't complain too much. Until the OS vendors include drivers for some of these "standard" devices like DFU, there is no incentive for device manufacturers to switch away from serial.
Serial has one huge advantage... its a standard..
I used to wonder why people didnt start embedding usb to serial ports on their devices until i started using one on my laptop... there are several chipsets out there with various quirks, and the place they are most used will mean these kind of barriers are fairly insummountable.
I have a sheeva plug and it does use an embedded usb to serial converter, but that device is a good example of where it would work and most places it wont.
What im refering to is of course the data center, serial ports thrive here because so many devices have serial consoles and this is a VERY VERY GOOD THING. As I said before, its a standard. I can buy a cisco (or any brand really) serial concentrator and then manage ANYTHING that has a serial console. Can you imagine the nightmare that would erupt if we went to usb consoles? "I have a cisco usb console concentrator, and its not compatible with our HP procurves or our dell poweredge devices"... dear god I hope they never ever do that. Buying cheap usb to serial converters for the people out in the field that need to get on consoles is far easier and cheaper. The vendor lock-in insanity would be such a painful experience here. On top of that, you can route most serial consoles over standard cat6 cable (huge bonus in the DC).
While pinouts (for serial) on some devices may differ, they really aren't any where near the agony of what a usb console would be.
As for speed, what device on earth has a serial console for more then a command line? I cannot think of a single device that was build in the last 10 years (perhaps even 20) that would require you to (or even let you) upload a firmware over its serial console. Even when truely broken, devices can usually get to their network ports for tftp or something similar. I hope to god the OP gets a clue because its an appalling suggestion that I hope never reaches the light of day that could only come from someone who really had a rough day with one particularly strange device and decided to have a whine about it on slashdot and try to apply it to a more general set of circumstances.
Seriously!?! Non-standard pinouts. I've been using non-standard pinouts for, what?, 25 plus years!?!
Are you a consultant for the USB lobby, or are you just mildly retarded?
What?, are you expecting some pretty little GUI to configure your fibre channel switches or something?
Or were you just trolling for flames?...
Damn web 2.0
Meh - too true...and can you do some basic, loop-back debugging on a USB port with just a bent paper clip? I think not!
Then again, it's hard to take anyone seriously that uses Windows in a server role.
You fail to account for server software that's Windows-only. I'm not talking about the core functions (file/print sharing, DHCP, AD/LDAP, LAMP), because *nix does work extremely well at these tasks and I won't at all debate that. In the office I work in though, they rely on financial software that is exclusive to Windows for both clients and servers. SHOULD the vendor write a Linux version of the stuff? probably. Given that my company has already spent mid-five-figures on a Windows infrastructure that works (yes, our servers do in fact function well enough to keep the company humming along on a day-to-day basis) and the software that holds their financial and client data (and Exchange and Sharepoint), why would my company care enough to switch to Linux? Answer: they wouldn't. If you don't take me seriously, then fine, I won't stop you from having your own opinion. At the end of the day though, the servers work, the clients work, the office staff is happy, problems are manageable, and I get my paycheck at the end of the period, so my regard for your opinion is somewhat limited.
The bottom line is that serial ports are still leet. I don't see why they should phase them out. I use a crappy Pentium 133mhz Laptop running NetBSD for my console work. when it dies, I will buy another one for $30 on eBay. I always thought it was for security anyway. Being able to only admin certain features of routers and other devices using only the serial console. nothing wrong with that. plus, a lot of the firmwares I've seen can be installed via TFTP server and you don't even need to transfer anything over the serial connection. it's there merely as means to administer the machine. all hail the serial console. and the pinouts are easy as shit. there's only 9 freakin pins for christ's sake and all 9 of them aren't even used half the time.
*plays the Apogee theme song music*
When you need third party software to use it that adds to the piles off annoying stuff to maintain and configure. Before I knew I needed to use a serial port at work I bought a Thinkpad without one. The truly maddening thing is, the Thinkpad's mobo HAS a RS232 chip on it but there's no fricken serial port on the laptop! I think IBM made a serial port Ultrabay module for my R40 (yeah it's a dinosaur now) but I could never find one at a reasonable price.
Damping absorbs vibrations. Dampening is caused by moisture.
With a network port and 64 serial ports. It is kind of overkill. You can telnet into the box and then switch to any serial port.
Zing!
Where are the usual MSFT ass lickers to shout you down? Oh, they're busy rebuilding their systems after the latest malware disaster. Heh.
Damping absorbs vibrations. Dampening is caused by moisture.
The HP StorageWorks P2000 G3 disk arrays have only USB and TCP/IP management. For most operating systems that support USB serial devices you can just plug it in and it'll be recognized. For Windows you have to download and install an INF file before Windows will see it.
yeah, its been dead quite a while. for those so inclined major vendors offer ILO cards and even the wips themselves are controllable through the network. even if you dont want the ILO card, the BMC chip can often interface on a specific vlan over the network, supports cryptography, and interface failover.
digis are in my opinion a dead relic these days
Good people go to bed earlier.
Amusingly, several oil and gas rigs in the north sea have HMI systems running on windows server 2003.
It is very stable due to the controlled environment of the system. So blanket statements like the one you made just make you look like a zealot ;)
Cisco (and other router/switch/telecom manufacturers) need to add a USB gadget (so it can plug directly to the USB port on a PC/laptop/netbook) console port. FYI, I am NOT saying to get rid of the serial console port that typically has an 8P8C (commonly misunderstood as RJ-45) connector. Just have both. The USB console should work as a serial console (using a widely compatible chip like FTDI). But they can also add additional features such as presenting flash storage on the equipment as a hard drive to the PC (ready to make backups of, or reload firmware and configurations onto, at full USB speeds), and even create a network interface for that PC/laptop to use (ethernet/IP over USB and ethernet/IP over PPP over a 2nd emulated serial port).
My cheap $90 point and shoot camera has a USB gadget port (although with no need for a serial port emulation). Why can't Cisco add that?
now we need to go OSS in diesel cars
There are a lot of crappy ones out there that don't work with a lot serial devices. The one that works best has a FTDI chip such as Cable Unlimited USB-2920 product. You can also go to FTDI's web site to get the latest drivers including support for Windows 7.
so you want to be a serial killer?
Nah ... a Real Man's console looks like http://en.wikipedia.org/wiki/File:IMSAI8080.jpg ...
One difference: you can use an IMSAI console with just your OWN fingers and toes. You don't need to color your own "Twister" game onto the console and throw a party. "Left nose Blue!" never worked well unless Alice the Alien could join in (at which point we're clearly talking non-Men).
One thing both those machines do illustrate is the serious deficiency, in modern computers, of blinkenlights.
In the offshore industry you still have those panels....
They are called "CAP" or "Critical Action Panel" and are connected directly to the low level controllers in the process and safety system bypassing all HMI.
Sometimes you want a hardwired connection to the device responsible for releasing a deluge valve. Gas-producing rigs in the north sea would be one such place *grin*
While an amusing joke, they still exist to some degree!
Most of what's being called serial here is asynchronous serial, meaning there's no external clock line. Each end of the connection has a clock that determines the baud rate, and so they must match in frequency within a couple of percent. There's a TX transmit line and an RX receive line and a ground wire in the minimal configuration. In a pc or an MCU there's a chip or an emulated version of same called a UART Universal Asynchronous Receiver Transmitter that takes care of buffering the serial bits as they come in (or go out of) the data wires One Bit At A Time. Many microcontrollers have built-in UART's. It used to be that the signal from a UART was universally converted to RS232 voltage levels. The spec says -12 volts is a 1 and +12volts is a 0. This is a really old standard that was invented to connect dumb terminals to mainframes through a modem. Several other wires are in the spec have to do with flow control and interacting with the modem. To get from 5 volt (or whatever) logic levels, a special line driver is used. A popular one is the MAX232 series of chips. These days the other lines in the RS232 cable are rarely used for their original purpose. The Arduino uses a flow control line to start the flash burner through a bootloader for instance. Async serial is very much still around because there are a large number of periperal chips and board-level modules that use a UART to communicate with an MCU or each other (sparkfun.com). In these applications, the voltage is at logic level. It is not shifted to RS232 levels, although you could do this if you needed to.
The serial port on the original PC is a DB9 connector. The UART's interface to the CPU is interrupt driven, so you can do pretty good real-time stuff. Since the async serial port us pretty much gone on PC's, a lot of devices like most cell phone cables use an emulated UART port running over USB. There are a couple of companies that make USB to 5 or 3.3 volt UART converter chips that implement the USB protocol. Rather than having to put the USB protocol it in the target processor, you buy the functionality. Of course there are MCUs that know the USB stuff, but they're a bit uncommon. Also there's the whole licensing problem if you roll your own USB device. So as strange as it is, designing with an 8-bt MCU, you'll use a chip with a lot more horsepower than the target to handle the USB interface. This is a very, very common thing to do. The other half of the problem is the host device drivers. FTDI make chips with no-cost drivers that are routinely used alongside a lot of 8-bit MCUs. There are drivers in the linux kernel for a handful of converter chips, and FTDI's are the best known.
The PITA for embedded designers is that the serial port emulated by the FTDI chip has buffering constraints and timing limitations (16ms latency) that basically ruin the real-time capability of the port. This really sucks. The alternative is to write your own drivers for Win, Mac, and Linux, and program your mcu to use one of the faster modes in the USB protocol than the one offered by the USB device class that includes async serial. For most people this doesn't matter. The host app on the PC uses its driver package that comes with, and you never have to know that your cell phone is using a 50 year old data link to talk to the pc.
I mean, it's the ultimate standard. Right? 2,3,7 - swap 2&3 if things don't work. Well, there is sometimes that pesky DTR signal, so sometimes you have to hook up 20. Unless you swap 2 and 3, in which case you need to swap pins 20 and 6 too. Then, sometimes you need DSR, so just hook up six. Unless you swapped 2 and 3, then you have to swap 6 and twenty for that. Of course, then there's the device that emulates a MODEM and you have to hook up CD ...
Yeah, serial interfacing is just so straight forward and simple, we can't get rid of it! :)
I keep an old laptop with a serial port, so that I can transfer stuff to my good old Atari 800XL with the awesome SIO2PC cable from Nick Kennedy: http://pages.suddenlink.net/wa5bdu/sio2pc.htm
I have to agree with you there. USB has just too damn many strange things that have to happen to even get the thing to work. I have written some USB code and I can say, with authority, that USB just sucks.
Hey KID! Yeah you, get the fuck off my lawn!
I made my own, more or less home-brewed, networked, serial, multi-console, hmm, can I put any more adjectives on that? Anyway, what I did was very simply, sort of: you take a big pile of USB-to-Serial devices, a suitable number of USB hubs and connect them to your (Linux-) system. The you start up a minicom on each of them inside screen, running in detached mode; you can now connect to the Linux system with ssh or telnet and attach to any of the screen sessions. The Power of Linux, Mwahahahaha!!
Yeah, I tried to put XP on my new machine a couple years ago. It couldn't see the RAID array, so I grabbed the driver CD and pressed (whatever) to load the driver.... and it said INSERT FLOPPY DISK! WTF?!? It might as well have said "Insert papyrus scroll"!
If a job's not worth doing, it's not worth doing right.
it's hard to take anyone seriously that uses Windows in a server role.
It's harder to take seriously anyone who can't manage to grok the fact that Microsoft sells a server OS that actually works for a large number of entities, and that some aspects of its functionality are unavailable outside of the Windows OS.
If a job's not worth doing, it's not worth doing right.
You're missing the point. You essentially have to hack the registry and add the drivers to the install image. You can't just stick a CDROM in with the drivers, because the OS doesn't support loading drivers off anything but a floppy as it is configured out of the box.
If a job's not worth doing, it's not worth doing right.
Not terribly hard to find. Not $300, either.
I had been erroneously thinking that the sliding switch on the side of an SD card was disconnecting something electronically, but you seem to be correct: the write-protect function is actuated by the software querying the state of a mechanical sensor.
On the other hand, this doesn't seem to be any different than the write protect tabs of floppy disks (which is what he's relying upon instead).
Barbie oyunlar kiz oyunlar Php dersleri php eitimleri thank yo
The nifty thing no one has mentioned about serial communications is the ability to provide reasonably reliable remote access into remote equipment. I worked for a consulting and services group which always located at least one modem into each customer site. That modem linked to a terminal server where access to firewalls, switching, routers load balancing equipment, servers and in some cases storage was available. If you can't reach a site this can answer all sorts of questions and provide a really fast way to put a customer back into service saving the time and potential travel costs.
If the widget is right next to you, USB or even network connection can make a lot of sense. If you're forcing a switch to fail over or rebooting a server from a PDA with a modem, serial is the way to go.
Who modded this "insightful"? Are you kidding me? I like Linux as as much as the next guy but for a business application Microsoft Server it can't be beat for ease of management. Sure Linux may run longer without updates, have fewer security holes, etc but MS hands down has the market cornered on easy to use.
It has one built in so you just connect your other machine to it via standard USB cable. It's good and puts the two-converters and a null-modem cable solution I had for my older NSLU2 systems to shame.
There are things that Linux doesn't do (or doesn't do well) and Windows does.
It seems it must be often cheaper to run redundant Windows machines for critical applications than to re-invent all the DCOM / .NET plumbing that is available for free on Windows Server. A lot of mission critical computers run Windows, presumably because free market capitalism determines that it is cheaper to run redundant Windows Servers than to try and reinvent all the capabilities that they provide in Linux / Unix / whatever.
You may be surprised how many critical computers run Windows Server. Love it or hate it, DCOM (Classic OPC) and the .NET framework (OPC UA) have provided very attractive functionality to the process control industry. Yes, the servers crash once in a while and you have to carefully manage patches, which is why you always run them redundantly and keep them syncronized for critical operations. And you may need to keep them on an isolated network. But in reality this isn't much different from embedded computers used for critical appliations that don't run Windows that also are typically used in redundancy.
Sometimes Windows Server is more fit for the job than Linux / Unix. Not all servers just serve up files, network services, databases, ftp, and HTTP. Sometimes Windows Server isn't fit for the job. But you should be open minded enough to use the best tool available to you to solve the problem at hand.
a bus. It is actually a hub and requires that one end-system be a controller (Intel's euphemism for a PC), a non trivial piece of silicon when compared to the slave. Other alternatives like Ethernet and Firewire (IEEE1394) never became popular enough for peripheral devices. So, the economies of scale are not there. Ethernet (i.e., 100BASE-T) might work. However, the specification requirements to drive the signal 100 meters make the interface too expensive, power-wise, for battery operated devices, and POE makes the power side more expensive. There is also the cabling issue. Firewire is truly a bus, but the silicon is still pricey when compared to USB 2.0, and there still may be a 25 cent royalty (per device) from Apple.
Of course - but they are usually not "pinned out" on comerical devices. I've had a pile of these gizmos and only one had a RS232 port.
Jibe!
In the past when serial interfaces were implemented with UARTs. Things were very stable. Once you got the cable, speed, bits... right, things were usually VERY stable. I have noticed that since serial ports have become IP blown into gate arrays, and more recently with these USB/serial converters, things are not reliable at all. I get things running, then for no reason, things hang up, and for no reason start working again. This is maddening for a software/hardware engineer used to having things that work, continue to work. While these interfaces are going to be around for a while longer, they are no where near as fun as they used to be. My recent experience using ADTPRO to bootstrap a bare-metal Apple ][ was an exercise in heartache. Armed with gender changers, null modems, serial breakout boxes, and plenty of little wires, things seem much harder than they used to be. We really need something else to become ubiquitous and usable, sooner than later, this is making me nauseous.
ilo and winimage or floppy images on a bootable cdrom has eliminated any need I've had for an actual floppy drive in a long time and on the plus side it's also generally faster.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
How the hell is this "Insightful"?
Anyone who actually says something like this in the IT industry is probably wondering why they're still working level 1 support.
Slashdot, you disappoint.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
It seems to have been overlooked in that a lot of large enterprise settings, the SPARC based servers are still loaded with the old RS232 as well. Personally I love the damn thing (RS232) and would rather see a resurgance in it's popularity. Even if that means a serial RJ45. It just works. Leave it the hell alone.
Just bought a managed DS-3 from ATT and wouldn't you know- we have the same thing! When we replaced our old managed line I figured the US robotics MODEM was just a relic. But then showed up my new 3800, and a brand new, shiny, in the box, US Robotics modem. I mean seriously? I had a smaller 56k line when dial up was still the thing at home...
USB is like ice hockey. It's fast, exciting, and sexy. All you need to do is keep your blades sharp, wear the proper protective gear, and hope your Zamboni or ice-making equipment does not break down during international competitions. You also need years of expensive training to play it well. Other than that it's great.
Serial ports are like soccer. All you need is a ball, you can play anywhere, and anyone can play.
Yep, won't be long before we'll be asking when the world will switch over from soccer to ice hockey. Or from serial to USB.
I've seen drivers mentioned a few times as an issue with USB serial adapters, but something I haven't seen mentioned yet is the fact that these drivers are usually (or always?) tied to the OS, which means the device can't be used until the OS is running and the driver is loaded.
From the client perspective this isn't a big deal. Eg., when using a USB serial adapter on a laptop to connect to a switch or modem, you're already going to have your OS up and running on the laptop. However, from the server perspective, this can be a major problem. If you use this on a server that, say, doesn't have a native serial port, nothing can be redirected until after the OS loads the appropriate USB driver. So, POST/BIOS messages, bootloader options, initial boot messages (eg., dmesg for Linux) are all unavailable. This severely limits the usefulness of USB serial adapters.
I think this problem needs to be resolved before USB can ever be considered a viable replacement, though personally I hope it does. It seems like it should certainly be possible; HID device (keyboard and mouse) support is offered by most BIOSes by enabling the "Legacy USB" support option, so obviously it's possible to talk to USB devices at this level. They just need to settle on a standard protocol for serial communication that can be implemented in a similar manner.
If serial goes away what am I going to do with all of these DEC and HP terminals I have laying around the data center?
DHCP for configuring a critical device is an utterly INSANE idea. The protocol needs to be PUSH, not PULL, for numerous reasons.
First, consider that the first time you connect to the device, you type in a static IP address. Great, EXCEPT YOU TYPED IT WRONG! Now it won't grab the DHCP address, and the device is now completely unreachable... via it's supposed MANAGEMENT INTERFACE. Great! Now you need to go plugin the serial cable to fix the management interface, or hard-reset the device, losing all the configuration.
Or maybe consider that the network addressing was change, and the management port configuration wasn't... Sure, an administrative oversight, but one that happens. And now you're stuck.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
So what, what lights out management card does not have virtual CD/floppy/USB features?
If you are serious about remote management you need proper lights out management, such as ILO, DRAC, RAS etc. depending on your server vendor.
Put another way a serial console is not enough, you need to be able to give it a remote kick.
So what, what lights out management card does not have virtual CD/floppy/USB features?
If you are serious about remote management you need proper lights out management, such as ILO, DRAC, RAS etc. depending on your server vendor.
Put another way a serial console is not enough, you need to be able to give it a remote kick.
The majority of servers I manage are for small businesses, and the only ones that have lights-out cards in them are the ones where the customer needed a beefy server and it just happened to include the card. The few that do have the LO cards only support remote reboots and the remote console only works in the BIOS. The moment Windows boots, you need to have a license key...lame.
So yeah--I wish Microsoft was on the ball with Windows 2003 and had USB or CD support for loading drivers.
There's no place like
Ah, the pleasure of never being able to be up-to-date vis-à-vis the whirlwind advance of technology and commerce. Sorry to have burdened you with old information.
Chuck Swiger on the freebsd-questions mailing list pointed out that some USB flash drives have write-protect switches:
PQI U339H 8GB Flash Drive (USB2.0 Portable) Model BB18-8039R0151 - Retail
There is a way,and it's used by coreboot:
http://www.coreboot.org/EHCI_Debug_Port
Denis 'GNUtoo'