Peter Nachtwey
Member
Temperature Control using Micro Logix PID
The link is to a .zip file that contains a .rss file that implements PID temperature control on a MicroLogix. The program uses the simulation techniques that have been used in the Excel spread sheets.
To experiment try changing N7:0. The number should be in the range of about 700 to 4300 or 70.0 to 430.0 degrees and then monitor the trend.
Now I have some questions. The PID control seems very coarse. The time constants only allow a few digits of precision. Also, the controller gain Kc I used was 3.61 degree/% output, but I had to mulitply this by 163.84 to get the real controller gain that works.
163.84 is 16384 counts/100%. ALso, I had to leave the set point max at 16384 even though the highest set point I would use is about 430 degree (4300).
Any clues as to how to make this better are welcome.
The link is to a .zip file that contains a .rss file that implements PID temperature control on a MicroLogix. The program uses the simulation techniques that have been used in the Excel spread sheets.
To experiment try changing N7:0. The number should be in the range of about 700 to 4300 or 70.0 to 430.0 degrees and then monitor the trend.
Now I have some questions. The PID control seems very coarse. The time constants only allow a few digits of precision. Also, the controller gain Kc I used was 3.61 degree/% output, but I had to mulitply this by 163.84 to get the real controller gain that works.
163.84 is 16384 counts/100%. ALso, I had to leave the set point max at 16384 even though the highest set point I would use is about 430 degree (4300).
Any clues as to how to make this better are welcome.