Ny-Series Instructions Reference Manual (W560 - Omron NY532-5400 Reference Manual

Heating/Cooling PID Processing
Refer to the section on the PIDAT instruction (page 2-664) for details on PID processing.
Heating/cooling PID processing is used to find the manipulated variables using the PID constants for
heating control and the PID constants for cooling control. If MV is less than or equal to 0 in the previous
processing results, the PID constants for heating control are used. If the previous MV is greater than 0,
the PID constants for cooling control are used.
Proportional (P), Integral (I), and Derivative (D) Actions
Refer to the section on the PIDAT instruction (page 2-664) for details on the proportional action (P),
integral action (I), and derivative action (D).
2-PID Control with Set Point Filter
Refer to the description in 2-PID Control with Set Point Filter in the section on the PIDAT instruction
(page 2-664) for details.
Heating/Cooling PID with Autotuning
You must use the optimum PID constants to execute this instruction. There are the following two ways
to achieve this.
 When Optimum PID Constants Are Not Known
If you do not know the optimum PID constants, perform autotuning at the start of operation to find
them. Change the value of Run to TRUE while the value of StartAT is TRUE. First, autotuning is exe-
cuted, and then heating/cooling PID control is started with the PID constants that are found.
 When Optimum PID Constants Are Known
Set ProportionalBand_Heat, IntegrationTime_Heat, DerivativeTime_Heat, ProportionalBand_Cool,
IntegrationTime_Cool, and DerivativeTime_Cool to the optimum PID constants and then change the
value of Run to TRUE.
ProportionalBand_Heat, IntegrationTime_Heat, DerivativeTime_Heat, ProportionalBand_Cool, Inte-
grationTime_Cool, and DerivativeTime_Cool are in-out variables. You cannot set constants for the
input parameters. Always define suitable variables, and then assign the values to input parameters.
You can change the PID constants during operation. You can also perform autotuning during opera-
tion. To start autotuning during operation, change the value of StartAT to TRUE.

NY-series Instructions Reference Manual (W560)

2 Instruction Descriptions
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