godcixelsyd
Member
Hi all, I'm not sure if I have selected incorrectly when setting this up, if I have something hooked up wrong, or if I'm missing something on the PLC side.
I have a humidity sensor : https://www.omega.com/temperature/pdf/HX71.pdf (HX71-MA)
Power Supply: https://www.automationdirect.com/ad...VDC,_12VDC,_48VDC,_DIN_Rail_Mount/PSB12-015-P
and Analog Input card: https://www.google.com/url?sa=t&rct...al.pdf&usg=AFQjCNH-6bGA75rJ462p3KyWDxOgGu4Zqg
I'm going from the positive terminal of the power supply, to the red wire on the humidity sensor, then the black wire from the humidity sensor to the positive terminal on the PLC, then the negative terminal on the PLC to the negative of the power supply. When looking at the logic in the PLC my digital value is 4000 (100%), which reading looked like on 4-20mA it shouldn't have gone over 2000. I started to think maybe I had the dip switches set wrong and that it was operating 0-10v, which would have made sense giving full voltage at the tail end of a 4-20ma device, but this wasn't the case. Next, I tried putting a meter between the black wire and the positive terminal of the PLC and checking my mA which reads 1.21 mA. This is the only thing going to this PLC card, the rest of the analog is 24vDC and seem to work, but I can't find anything in the literature that says the analog card won't work with 12vDC. Any ideas on where I may have gone wrong?
I have a humidity sensor : https://www.omega.com/temperature/pdf/HX71.pdf (HX71-MA)
Power Supply: https://www.automationdirect.com/ad...VDC,_12VDC,_48VDC,_DIN_Rail_Mount/PSB12-015-P
and Analog Input card: https://www.google.com/url?sa=t&rct...al.pdf&usg=AFQjCNH-6bGA75rJ462p3KyWDxOgGu4Zqg
I'm going from the positive terminal of the power supply, to the red wire on the humidity sensor, then the black wire from the humidity sensor to the positive terminal on the PLC, then the negative terminal on the PLC to the negative of the power supply. When looking at the logic in the PLC my digital value is 4000 (100%), which reading looked like on 4-20mA it shouldn't have gone over 2000. I started to think maybe I had the dip switches set wrong and that it was operating 0-10v, which would have made sense giving full voltage at the tail end of a 4-20ma device, but this wasn't the case. Next, I tried putting a meter between the black wire and the positive terminal of the PLC and checking my mA which reads 1.21 mA. This is the only thing going to this PLC card, the rest of the analog is 24vDC and seem to work, but I can't find anything in the literature that says the analog card won't work with 12vDC. Any ideas on where I may have gone wrong?