Chapter 7. PARAMETER SETUP
●PA17 (PID computation initialize manipulated variable)
●PA27 (PID computation initialize manipulated variable)
Under the conditions listed below, a PID computation starts using the value set in
PA17.
•When there is a mode change from READY AUTO to RUN AUTO.
•When the controller is powered up in RUN (or HOLD, FAST, END) AUTO mode.
•When
Since the PV, SP and PID parameters affect a PID computation, the first manipulated variable of a PID computation may not be the same as the value set in PA17 and PA27.
●PA31 to PA38 (event on delay groups 1 to 4, event/delay time)
•On delay can be performed on up to 4 events.
•PA31, PA33, PA35 and PA37 determine which events are to be processed.
•In a code event involving several event outputs, event on delay has to be set separately for each output.
•All processes including event output standby on/off are processed before on delay processing. When the event output ON condition remains on for longer than the on delay time, the event output stays on.
•This is shown in the diagram below.
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●PA43 (PID computation initialize)
●PA96 (PID computation initialize)
When SP changes abruptly due to ADV, the derivative action of a PID computation, may cause an excessive change in the manipulated variable of the computation.
For this reason, the initialization of a PID computation is performed to suppress an excessive change.
But the initialization of a PID computation means that PID computation continuity is lost which may affect operating conditions. PA43 and PA96 settings allow the user to turn on or off initialization and determine its conditions.
