AH500 Programming Manual 3. To prevent the parameters which have been tuned automatically from disappearing after a power cut, users have to store the parameters in the latched data registers when is PID_MODE set to 1. The parameters which have been tuned automatically are not necessarily suitable for every controlled environment. Therefore, users can modify the parameters which have been tuned automatically. However, it is suggested that users only modify the K I or the K D . 4. The instruction should be used with many parameters. To prevent the improper control from occurring, please do not set the parameters randomly. Example 1:
The use of the instruction PID in the position control ( PID_MODE is set to 0 or 2.) Position command (SV) PID MV Plant Encoder PV Example 2: The instruction PID is used with the AC motor drives. ( PID_MODE is set to 0 or 2.) Speed command (S) Acceleration/Deceleration command (SV) Actual acceleration/ deceleration (P V=S-P ) Example 3: The use of the instruction PID in the temperature control ( PID_MODE is set to 0 or 2.) Temperature command (SV) Example 4: The steps of tuning the parameters used with the instruction PID Suppose that the transfer function of the plant is the first-order function ( ) a + s b = s G , the SV is 1, the sampling time Ts is 10 milliseconds.
It is suggested that the steps of tuning the parameters are as follows. Step 1: First, set the K I and the K D to 0. Next, set the K P to 5, 10, 20 and 40 successively, and record the target values and the process values. The results are shown in the diagram below. 6-178 + S+MV AC motor drives + Acceleration/Deceleration output (MV) Speed tion PID detector (P) AC motor drives PID Speed detector (P) PID Heating (MV) Heater Temperature detector