IDEC MicroSmart Pentra - Manual (Page 113)

C ONFIGURING PID M ODULE USING W IND LDR
6-48 FC5A MicroSmart PID Module User’s Manual FC9Y-B1283
(3) Control Register+182: Wait Value
During the program control running, when a step is finished, the PID module checks whether the deviation
between the process variable (PV) and set point (SP)] is less than or equal to the wait value. The program
control is not proceeded to the next step until the deviation becomes less than or equal to the wait value.
The wait function does not work and the program control is proceeded to the next step if the process variable
(PV) satisfies the following condition:
Set Point (SP)
– Wait Value ≤ Process Variable (PV) ≤ Set Point (SP) + Wait Value
Example 1: Wait function when the temperature is rising
Example 2: Wait function when the temperature is falling
How to Cancel Wait Function
The wait function can be cancelled for the program control to proceed to the next step by turning on the
advance next step bit, which is the bit 6 of the operation parameter.
Step (Wait value is set)
Time
Set point (SP)
Set point (SP)=500
490
T T
Wait value: 10 C
Moves to the next step when process variable (PV) reaches 490 C.
Set point (SP)=500
510
Time
Set point (SP)
T T
Step (Wait value is set)
Wait value: 10 C
Moves to the next step when process variable (PV) reaches 510 C.
: Program pattern
: Process variable (PV)
: Program pattern delayed by T due to the wait function