I am new to this analog stuff and am having problems understanding the value or scaling or ?? when passing data between an analog input card and the PID control block. We have a pressure transmitter scaled from 50-150 deg F (4-20ma) to a 1771-IFE/C analog input card (channel 3) on an AB PLC-5/30 . The raw data is 0-4095 in the input card.
When the data shows up at the PID control block it looks like its in different units (decimal?). I would like to be able to enter my set point in degrees F. and have the process variable show up as 50 - 150 degrees.
PID Configure Screen
PID Status Screen
I have read a ton of stuff on this site and it has gotten us to the point where the steam valve that this PID is controlling actually works. I just don't think I should have to figure out that 10,340 set point = 120 degrees. Any help is appeciated.
When the data shows up at the PID control block it looks like its in different units (decimal?). I would like to be able to enter my set point in degrees F. and have the process variable show up as 50 - 150 degrees.
PID Configure Screen
PID Status Screen
I have read a ton of stuff on this site and it has gotten us to the point where the steam valve that this PID is controlling actually works. I just don't think I should have to figure out that 10,340 set point = 120 degrees. Any help is appeciated.