Slashdot Mirror
Can You Build a Fiber Test Kit On a Budget?
An anonymous reader writes "Have any Slashdot readers hacked together cheap test kits for fiber optic cable? More and more IT infrastructure is using multimode and single mode fiber optic cabling. Commercial test equipment is extremely expensive, running the gamut from a few hundred dollars for a basic light source, to tens of thousands for an OTDR. What equipment do you consider essential to your fiber kit? Is there a way to save costs when it comes to fiber test equipment? It is worth it to do so?"
Two Media converters. If you can run ethernet over it, it's good.
No. You get what you pay for.
If your budget is $1 million, no problem. If your budge is $5, problem.
Depends on what you need to do.
There are many different tests you can do on fiber. A basic college course will teach you that.
Do you just want to know if the fiber is not "broken"? a LED and a phototransister can do that.
Want to know if the fiber is the correct mode, optimized for the wavelength of the led, or can support multimode and run parametric tests on the fiber, gee, that gets more expensive.
Its the same for the DIY ethernet cable testers too.
Want to test continuity? a 5$ multimeter will do that.
Want to determine if the cable meets spec? You need better equipment.
Better Equipment GENERALLY equals better [test] results. [ yes, a lot can depend on the skill of the tech operating said equipment too].
Nick one.
+1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
Try a flashlight!
"We are the music makers, and we are the dreamers of dreams [...]."
Everybody has used the flashlight (or desk lamp) approach to testing fibre. One step up is a small project box with a battery and LED in it, drill a small hole in line with the LED that you can put the test cable into. The other side is a project box with battery and phototransistor hooked to a beeper (or alternatively to a small current meter ). The light from the transmitter box runs through the cable and hits the detector box and makes noise or moves the needle on the current meter. While its by no means accurate for a measurement its good enough to tell you if the cable is cut or badly damaged. In general I'd expect similar results from each strand in a multi-strand bundle.
"running the gambit" I don't think it means what you think it means.
OMG! Wau!
Please, for god's sake editors, do some editing.
It's "running the GAMUT," which means "the full range or compass of something; a range from one extreme to the other"
GAMBIT, on the other hand, means:
1. Chess. an opening in which a player seeks to obtain some advantage by sacrificing a pawn or piece.
2. any maneuver by which one seeks to gain an advantage.
3. a remark made to open or redirect a conversation.
But I could see how they could be confused, they both start with a G and have vowels *rolling eyes*
http://www.weetabix.co.uk/
"The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
I thought it was running the Gumbo... If we're following the 'starts with G and has vowels' rule than that'd work perfectly.
Confucius say "cheapest way to test fiber is to eat cow pie."
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
That begs the question of how long it will be before a large number of repliess along the lines of "languages evolve" "if people use it to mean that then that's what it means" or "so what, I understood it" will arrive.
Only three things are certain; death, taxes, and apocryphal quotations - Ben Franklin.
Ah, but it is correct. "Running the gambit" would mean, essentially, "playing the game". The commercial test equipment manufacturers are maneuvering price points and feature sets in order to gain the advantage of making a sale. So, they are "running the gambit", ie. playing the marketing game.
Okay, I can't keep a straight face anymore. It is gamut, not gambit. But I held it together pretty good there, for a while.
When our name is on the back of your car, we're behind you all the way!
Please, for god's sake editors, do some editing.
Ostensibly they are quoting the anonymous user. Which is most proper: to correct such mistakes in quotations, to call them out with "[sic]", or let them stand?
For my part, I tagged with typoinsummary, runningthegamut, and !gambit.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Had to answer this question once ourselves. Never got to the implementation phase, but the plan was to have one or two high-end test sets, and build the others out of the prototypes for the equipment we were building, and Lucent OptiStar NICs on Linux systems. IE, each protype would test the next, and we would have racks full of 1U Linux Boxen with Lucen OC-12 NICs. Can't find out of Lucent or Alcatel-Lucent is still making those things, but you can find used/refurbed OptiStar (?) SONET IP Nics for Linux (PCI) fairely cheaply. No idea if they work, but as low as $60 bucks. New, they were $10k to $6k. Searching for Optistar on Ebay or Google returns a lot of info. Or, searching for SONET PCI NIC. Or, just FIBER PCI NIC. You can probably set up a laptop with Gig-E, if you just want connection tests, regardless of which protocol you're going to use. Honestly, eBay/Amazon are your friends here. At times, you can find million-dollar test sets for $100 bucks (Adtech, Omniber, Cerjac...) Most are left-overs from when startups fail. Also depends on what you're testing.
Here's to losing my Karma Bonus again....
I used to build fibre optic cables and every cable that didnt have glowing bits when you pushed a laser down them seemed to test perfectly. So I would use a 5mW green laser and if any bits on the cable glow you know that cable is broken.
Really, the cheapest solution is a simple power meter, some cable-cleaning swabs, and a nice long spool of pre-terminated spare cable.
There are full-fledged cable certification devices out there, and you cannot afford one, nor do you need one.
Yes, there are a lot of problems that can happen with a cable that won't be caught with a power meter, but those problems can be prevented by only using factory-terminated cables from a quality supplier.
SirWired
You can get these used on eBay all day long for a few hundred dollars for the entire set (search terms: "fiber test*" "fiber patch*" "fiber splice*"). You may have to watch a few days for a bargain, but I'm constantly amazed at how often high-quality fiber test gear goes for a song on eBay. Purchase only name-brand gear, such as Fluke, Noyes, Microtest, TestUM, etc. (You can learn the name brands by looking at new-equipment listings at places like CDW).
There are many tutorials on the web showing how to use these tools, most from equipment vendors themselves, and some are even high quality video presentations. A useful starting point is http://fiberu.com/ (although it's become less useful since Fluke took it over).
The mini-maglite will instantly identify any fiber -- the light will be clearly visible at the far end of even a thousand-foot run. If high-power IR lasers are in use on the network, be careful to be wearing fiber goggles whenever looking at fiber ends, even at your own white light. You can't tell when a fiber is energized with high-power IR, since it's invisible.
The power meter lets you measure the light loss through a fiber path, which when correctly interpreted will give you performance information. Get one that reads tenths of a microwatt, and that also directly displays dB loss from a reference signal. If you know the installed fiber specifications (you can read these off the fiber jacket), you can compute the available bandwidth based on fiber length.
The fiberscope reveals otherwise-invisible defects in a connector so that you don't spend hours trying to make an unworkable connection work. Again, be sure you're wearing laser goggles if you don't have both ends of a fiber in your hands. Magnifying harmful IR radiation is very dangerous.
For routine work you don't need an OTDR. Besides measuring the length of a fiber, an OTDR will locate defects along a fiber span so you can locate and repair them. If you're not repairing cable, or splicing it, an OTDR is overkill. Fiber installers have such gear, and they'll be happy to use theirs on your network for a fee when you need that capability.
Spend your money on the commerical stuff. It's just not worth it to do anything else. As previous posters have noted, use ebay or some reseller. There are some that specialize just for fiber optical equipment.
You need to have
1) An optical power meter that handles multiple wavelengths and can measure at least 0 dBm.
2) A video optical scope. Do not get a passive scope. You'll burn your eye out. Westover scientific sells a great hand-held, USB scope for about $2k-$3K. It's worth it. Get it.
3) A cletop, optical pads, "soft" and "hard" swaps, and some alcohol (for the ferrule, not your body)
If you are going to use DWDM you need an Optical Spectrum Analyser. Aglient is the best but there are others. There is a real cheap handheld that interfaced with LabView (or something) that someone was trying to market for about $2k-$3K but I can't find the page.
If you are doing long distance fiber work, you need an OTDR. No alternatives. Buy an Aglient. (I like them, can't you tell) If you just want to see if you have a fiber break, buy a light source from NOYES or anybody. That with the power meter will tell you if something is wrong with a short piece of fiber.
Hasn't "language evolves" come to mean "I can't wait until the ignorant take over the world?"
Oh, wait.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
There's a really cheap "laser" detector that nearly every tech carries, although you may have forgotten it.
It's that camera on your cell-phone.
Yup, in a pinch, you'll see a nice little purple dot appear on your screen if you've got IR coming down the fiber. Works well enough to identify active cables.
You can also pick up a mag-lite->fiber adapter that'll shine visible down the line fairly cheap.
Support FSF: Stop thinking with your wallet, and think with your imagination. (cc/non-commercial)
http://www.youtube.com/watch?v=UYks5sNrEfc
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
Im active duty, and in my shop we use a LS/PM model TS-4358 made by EXFO AMERICA. For an OTDR we use an ACTURNA MTS 5000 measurses 850nm and 1300nm wavelengths. The machines are simple to use but have many options.
Multimode fiber reels that I repair come in 500m lengths. I use my led Maglight for simple testing of it passing light or not. So easy a caveman can do it.
Im sure the civilian market has higher standards of min dB loss then the military.
I thought it was running the Gumbo...
Nah, any halfway decent gumbo will be too thick to run.
Although I suppose gumbo could be used in a different kind of "fiber" test. :-)
I see even classic Slashdot is now pretty much unusable on dial up anymore.
I remember when I was a kid I had a lego spaceship that had fiber optics on it.
They didn't do anything but they sure looked cool!
Wait, what were we talking about?
"Computers are useless. They can only give you answers." - Pablo Picasso
You should never hold fiber to your eye, as you should never hold a gun towards you.
Buy 2 fiber collimators (they're cheap and you can get them from anywhere that sells laser optics like scientific atlanta). Shine a flashlight down one columator, then...decollumate the beam and shine it on a white surface. You should see even illumination all over the circle. If there are little shooting stars of light around the edges...you've got a problem with your termination.
You can compare new fiber to the fiber you want to test to get a sense of how bright the light should be.
hope that helps...but...please....no fiber to the eyes. The pulses that are used in Fiber Channel and Ethernet fiber can damage your eyes!!!!
You can get a 1gb FCAL fibre channel HUB for next to nothing. Most people throw them out. But with just two GBIC's installed you can put a fibre cable on it and it will go through its Loop Init and link give you link lights. With some SC/LC adapters you could at least test multimode fibre.
As some pointed out.. what is defined as 'Cheap'? And also what level of work are you doing?
If you're just a cable/server/network guy (like me) then you really just need a cleaner and something basic to check for breaks.. (see comments about mag-lites; etc). I mostly deal with pre-made patch MM/SM.
A decent DB tester on 1300/850 is helpful too just so you can check for light-loss assuming your optics don't tell you (some do).
If you are a 'Fibre Guy', or make your own SM/MM; then you'll want to look at things like Fusion Splicers and OTDRs and other (generally expensive) test kit.
----- The internet has given everyone the ability to have their voice heard equally as loud.. even if they shouldn't be