High density RTD/resistance input cards

[RyreInc]

Hello, I am looking for an analog input card or device that measures resistance, and interfaces with an Allen-Bradley PLC, preferably using Ethernet/IP. The measurement repetition rate should be less than 500ms or so, ideally less than 100ms. Resistance range is about 50-500Ω. We need 48 channels, so high density is valued. 12-bit resolution should be sufficient. What options are out there?

I have explored the brands Wago, Allen-Bradley, Advantech, B&R, and Beckhoff so far, but each of their solutions has various drawbacks.

I am open to using a voltage input card, but the full scale range would need to be around 200mV, not the standard 10V. And plus going that route would require pull-up resistors, complicating the panel wiring.

 

[IRstuff]

Keithley is still king

https://www.tek.com/en/products/keithley/digital-multimeter/keithley-daq6510

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[RyreInc]

Thanks for the quick response IR. Looks like that Keithley solution is close, but it looks like it does not offer any industrial comms protocols such as Ethernet/IP, Profinet, Modbus/TCP, etc. This needs to interface directly with an Allen-Bradley PLC.

 

[IRstuff]

The webpage I linked says "Standard LAN"

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[thebard3]

Spectrum Controls has a line of analog input modules for Control and Compact Logix controllers. I use 1756-IF8Usc and 1769-IF8Usc with good success.
Link

Brad Waybright

The more you know, the more you know you don't know.

 

[danw2]

Acromag's busworks series is modular I/O with preloaded comm protocols (including Ethernet/IP) in the bus network module.

The 6 minute video is a good summary:
Link

voltage input modules on this page:
Link

I didn't read closely enough to see if the RTD resistance input module would do 2 wire raw resistance over your range, but most I/O modules do.
temperature (resistance) modules on this page:
Link