Using TCP/IP for Data Logging

[jamesfkelly 0]

Hello again, I am working on a way, by any means and on any PLC really, to log data at a rate of 100 Hz, I expect to have around 75 points give or take and need to log at a high sampling frequency for analytical purposes. This has become a major sticking point in project development. One idea we are kicking around is using the Ethernet port on the ComplexLogix device to stream raw data to a PC where the data can then be logged by the PC. My question is, would this be possible, has anyone done something similar, or does the Rockwell software simply make that impossible. Also, I am looking into other PLCs, Mitsubishi and Siemens at the moment, to see if they can help me log data at this frequency, and if anyone knows anything about either of those and their data logging, advice there would also be welcome. Thanks as always for your help, James

[Ken Roach 194]

Most commercial data collection software uses an unscheduled mechanism to poll data from a controller, so speeds like 10 ms update intervals are hard to accomplish. It's just not how things are often built. But it's right in the sweet spot for an I/O connection over EtherNet/IP. If you are experienced software developers you might start with the recent open-source project for an EtherNet/IP I/O stack, or go with a commercial product. I have seen good success with Hilscher, HMS Fieldbus, and especially with Pyramid Solutions. http://sourceforge.net/projects/opener/ At 10 ms you are getting into the low end of how fast typical data acquisition channels run... if it's analog you're going to need the Fast Analog modules and if it's digital consider the filters in the cards you select.

[lostcontrol 23]

Even though this is in the AB section Omron make a product called a SPU I think: http://www.omron-ap.com/product_info/CS1W-...5B%5D/index.asp This says it can go down to 5mS, but you would have to read up a bit more to confirm if suitable for your application. This may suit though, as I would think that 10mS logging on a PLC would be quite resource intensive. They may be quite pricey though.