Electroman

I'll be regulating a few different voltages. I will be using a voltage divider on the analog input to get the range the PLC is looking for, and a voltage amplifier circuit to drive a triple darlington pair to control my output. Making that part of it work will be easy. I never see changing the preset value in the system more that 10-15% from where I set it initially. I just can't get the ladder logic I need figured out. I'm going to try a search for PID loop and read up on that.

I did try searching, but couldn't find anything. I am looking to use my CP1H-XA40DT1-D's analog output to drive a pass transistor while monitoring the output of the pass transistor for a regulated power supply. The physical part of it is easy, but for some reason, I can't get my mind wrapped around how to do this in a ladder. I rarely deal with analog's, so I feel like a fish out of water on this. Any help as to how I should approach this, or what I might search for would be a great help. Thanks.