1746-NI4

[Guest William]

What I would like to know is if you can hook up rtd temp. sensors or other temp. sensors to the the slc-500 1746-NI4. If so how? Or would it be cheaper to buy a 1746-NR4 for temp.

[Ken Moore 23]

I don't think you will have much luck trying to hook up RTD's to a NI4. You may want to look at the universal input card from Spectrum controls, they are an AB partner. The universal card handles all types of analog inputs, voltage, current, RTD, TC. This is the link: http://www.spectrumcontrols.com/ab-1746.html

[Ken Moore 23]

oops, forgot to add the clip from the manual Edited 5 Nov 2004 by Ken Moore

[Guest William]

Thanks for the info. Not sure this is cheaper that the ab module but will check. The sensors I need to install are 10 to 25 feet away form the PLC. Any info on sensors would be helpful. Just need to check 1st floor and 2nd floor and out side temps. Looking for good but cheap sensors (Home project) William wdplymi@wowway.com

[Ken Moore 23]

I think you will find that thermocouples are the cheapest sensors. However, they can be a pain to maintain. Since they operate in the millivolt range, a slightly loose connection can drive you nuts. I usually use omega for thermocouples: http://www.omega.com/prodinfo/thermocouples.html If you decide to use the thermocouples, then your best bet would be a thermocouple input card for the SLC. You can buy a used (with warranty) 1746-NT4 from www.plccenter.com for about $475.00. You may be able to find one on EBAY for less, I did a quick search on EBAY for 1746-NT4, and found several for around $200-250 each. Generally speaking I buy used stuff for work, and EBAY is too much of a gamble. PLCcenter offers a warranty, and we have been doing business with them for several years. Hope this helps, others may be able to give you better advice. You can also try this forum: http://www.plctalk.net/qanda/ There are a lot smart people there also. Ken Edited 6 Nov 2004 by Ken Moore

[Snerkel 0]

For a home project maybe something like this would do the trick http://www.electronics-lab.com/projects/pc/010/ though directly interfacing to a PLC may be a little more difficult.

[guillencito 0]

William, you can attach a signal converter between RTD and PLC in order to make a stronger connection and minimize the signal losses. In my job we have used this converter to drive thermocouple signals and send them to 1747-NI4 input modules: ULTRA SLIMPAK #G428-0001 The manufacturer is Actions Inc. I think this device could drive RTD signals. You can check its info. Regards!