Basic PLC Analog Input Question

[am1]

Hi all,

I am using a B&R X20CP0483 system, I am working with a X20AI4222 module (+/-10V) for a simple FSR sensor . I have it wired and working in arduino (see image below for diagram), I have also wired it the same way on my AI mod (A0 is the AI+ pin, and the GND goes to PSU V- and AI-) and have it successfully working. However, since it is a 2 wire device, is there a simpler way to wire this on my PLC (so I can reduce cable wires needed)? DO I need to use the external PSU, or does the module (A+ pin)  simultaneously read the signal with power the device. Do I need a load resistor at all, or could it directly be wired to the module? 

[BeBuLamar]

The input of the B&R X20 which is like most other PLC's system. It expects a voltage which in your case from -10 to +10V. The sensor you have is just a resistor and it doesn't generate any voltage. You would have to somehow convert the resistance of the FSR to a voltage. Perhaps part of a voltage divider? Still you will have to do quite a bit of calculation within the PLC because the voltage won't be linear to the resistance of the FSR.