C_R_PLC Posted August 2, 2018 Report Share Posted August 2, 2018 So after a lot of troubleshooting I'm officially out of ideas, so hopefully someone can see what I'm missing. My current set up is 2 4-20mA pressure sensors hooked up to the 2 analog inputs on the V350-35-r34. Wiring is + to PLC input, - to power supply 0v which is commoned with the PLC, ground to ground. The jumper setup is A A B B B from 1-5, so just the analog jumpers changed over. I have tested literally every aspect of this setup, both sensors are a complete loop when tested, the PLC reads correctly if I use a 4-20mA loop simulator, all the wires are intact, I've tested it at the minimum distance of the wires, I've used 2 different PLCs, I've quadruple checked the program and all of that setup. I have literally no idea what is wrong at this point. Is there anything else anyone can think of to test or troubleshoot with this? Quote Link to comment Share on other sites More sharing options...
C_R_PLC Posted August 2, 2018 Author Report Share Posted August 2, 2018 This is the reading that I get no matter what I do. Quote Link to comment Share on other sites More sharing options...
MVP 2022 Joe Tauser Posted August 2, 2018 MVP 2022 Report Share Posted August 2, 2018 If your transmitters are two wire devices (loop powered) you have to hook + of the transmitter to +24V, - of the transmitter to the + PLC inputs. All that's connected to the + PLC input is a resistor to COM. Your transmitter provides the current that then provides a voltage to the PLC's A/D converter. Joe T. Quote Link to comment Share on other sites More sharing options...
C_R_PLC Posted August 6, 2018 Author Report Share Posted August 6, 2018 As always Joe you are a savior for my mental stresses, that worked. I was copying the wiring I had for another sensor but a wire must be switched somewhere along the way that threw me off. Thank you! Quote Link to comment Share on other sites More sharing options...
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