Talk:Control Systems/Controllers and Compensators

I will add basic PID discussion here (draft pad) I will add a jpeg link for a typical PID GUI. The GUI handles many desirable elements of the control including: 1. enable/disable/simulate 2. mode:  auto/manual/cascade 3. operator assist raise/lower (R/L) 4. indication of the quality of control 5. show setpoint(SP), input value(PV), and output(OP) clamps 6. clearly show output target selection when multiple choices 7. it is preferable to have warning of key events such as output being at its clamp, IO communications loss or primary/secondary cascading disconnect. 8. other parameters such as tuning gains can be edittable via alternate display layers not defaulted visible

Additionally, there are several control aspects which follow

a. secondary disable triggers primary disable b. in auto, operator assist targets SP; manual targets OP c. Primary cannot select cascade if secondary ctrl disabled or in manual d. secondary cannot select cascade unless primary is enabled and in auto e. outputs to field are blocked in SIMULATE mode. f. loss of IO comm, unavailability of output target prevent enabling the loop or disables an active loop.

Cascade mode is used when several variables/inputs affect the control. A primary/secondary cascade setup allows for other variables to separately target the setpoint of the secondary loop. --Billymac00 05:05, 8 December 2006 (UTC)

Here is a process display having pumps with PID control. Notice the pump radio buttons, which are the popup links.

Here is a recent reference on PID tuning - Handbook of PI and PID Controller Tuning Rules by Aidan O'Dwyer, March 2003 ISBN 186094342X.