I'm not too sure that I understand exactly what you want, but I'll give this a shot. From what I gather, you have X number of instrumentation installations spread around a local site. You want to collect the data from all of them with one central unit, and then dump the data to a PC. I would do one of the following...
1) Set up an RTU data recording device and attach it to each sensor collection point. Depending on the type of sensors you use (0-2.5V. 4-20 mA, RS-232 "smart sensors", etc...), you should be able to find a relatively inexpensive Datalogger/RTU that fits the bill. If it is to be located in a harsh environment (outdoors, cold, etc.), make sure you have a board and enclosure suitably rated for such conditions (you can find severe environment units from www.lakewood.com).
Next, get an RS-232 -> Ethernet device. ZWorld had a spiffy programmable one that can be found at http://www.zworld.com/emseries.html.
Finally, get an 802.11 wireless device and connect it to the ethernet output of the RS-232 -> Ethernet "modem".
The nice thing about this setup is that you don't need any crazy serial input boards or wireless RS-232 devices. Everything comes in through a nice packet switched TCP/IP network. This is a blessing for keeping the end user software simple and stable.
2) One other possible solution is to do all of the above, but with one change. Instead of the RS-232 -> Ethernet device and the 802.11 connections, simply attach a Mobitex, CDMA, or CDPD wireless device to the RTU's. Granted this has some more cost associated with the mothly fees, but most carriers have lower cost "data only" packages without all of the crappy consumer features that you have no need for. And again, this has the benefit of a packet switched connection. As well, if your sensors are REALLY far apart, this might be the most economical solution in the long run due to the extra cost of "repeaters" and such. Plus, most of these types of devices already have the capability to connect to RS-232 components without extra hardware. And, if you're lucky, you can get the whole package in a 99 dollar heavily subsidized digital phone from your favorite carrier:)
Just my humble opinion, from a humble man who has done these things before:)
Feel free to contact me on ICQ 34034928 if necessary. My listed e-mail is a fake:)
"You should read my new book: Humility, and how I attained it with 343 Illustrated Pictures of the Author."
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I'm not too sure that I understand exactly what you want, but I'll give this a shot. From what I gather, you have X number of instrumentation installations spread around a local site. You want to collect the data from all of them with one central unit, and then dump the data to a PC. I would do one of the following...
:)
:)
:)
1) Set up an RTU data recording device and attach it to each sensor collection point. Depending on the type of sensors you use (0-2.5V. 4-20 mA, RS-232 "smart sensors", etc...), you should be able to find a relatively inexpensive Datalogger/RTU that fits the bill. If it is to be located in a harsh environment (outdoors, cold, etc.), make sure you have a board and enclosure suitably rated for such conditions (you can find severe environment units from www.lakewood.com).
Next, get an RS-232 -> Ethernet device. ZWorld had a spiffy programmable one that can be found at http://www.zworld.com/emseries.html.
Finally, get an 802.11 wireless device and connect it to the ethernet output of the RS-232 -> Ethernet "modem".
The nice thing about this setup is that you don't need any crazy serial input boards or wireless RS-232 devices. Everything comes in through a nice packet switched TCP/IP network. This is a blessing for keeping the end user software simple and stable.
2) One other possible solution is to do all of the above, but with one change. Instead of the RS-232 -> Ethernet device and the 802.11 connections, simply attach a Mobitex, CDMA, or CDPD wireless device to the RTU's. Granted this has some more cost associated with the mothly fees, but most carriers have lower cost "data only" packages without all of the crappy consumer features that you have no need for. And again, this has the benefit of a packet switched connection. As well, if your sensors are REALLY far apart, this might be the most economical solution in the long run due to the extra cost of "repeaters" and such. Plus, most of these types of devices already have the capability to connect to RS-232 components without extra hardware. And, if you're lucky, you can get the whole package in a 99 dollar heavily subsidized digital phone from your favorite carrier
Just my humble opinion, from a humble man who has done these things before
Feel free to contact me on ICQ 34034928 if necessary. My listed e-mail is a fake
"You should read my new book: Humility, and how I attained it with 343 Illustrated Pictures of the Author."