Simple Two-Degree-Of-Freedom; Normal/Reverse Operation Selection Function - Mitsubishi Electric MELSEC iQ-F FX5 User Manual

4.7

Simple Two-degree-of-freedom

In addition to the PID control, this function selects a suitable response speed for the set value (SV) change from three levels
to simply achieve the two-degree-of-freedom PID control.
General PID controls are called one-degree-of freedom PID control. In the one-degree-of freedom PID control, when PID
constants to improve "response to the change of the set value (SV)" have been set, "response to the noise" degrades.
Conversely, when PID constants to improve "response to the noise" have been set, "response to the change of the set value
(SV)" degrades.
Compared to one-degree-of freedom PID control, "response to the change of the set value (SV)" and "response to the noise"
can be compatible with each other in the two-degree-of-freedom PID control.
Note that required parameter settings increase and it is difficult for PID constants to be automatically set by the auto tuning
function for complete two-degree-of-freedom PID control. Consequently, the temperature control module operates in the
simple two-degree-of-freedom PID control for which parameters are simplified.
In the PID control (simple two-degree-of-freedom) of the temperature control module, users can use PID constants making
good "response to the noise" and the form of "response to change of the set value (SV)" can be selected from the following
three types.
• Fast
• Normal
• Slow
Temperature process value (PV)
Set value (SV) 2
Change
Set value (SV) 1
Setting method
Configure the settings as described below.
[Navigation window]  [Parameter]  Target module  [Module Parameter]  [Application Setting]  [Control basic
parameters]  [Control Response Parameters]
4.8

Normal/Reverse Operation Selection Function

This function selects whether to implement normal or reverse operations during standard PID control.
This function can be used in all the control methods (two-position control, P control, PI control, PD control, and PID control).
(Page 26 Control Method)
For details on the operation, refer to the following.
Page 167 Actions of the temperature control module
Setting method
Configure the settings as described below.
[Navigation window]  [Parameter]  Target module  [Module Parameter]  [Application Setting] [Normal
Operation/Reverse Operation Setting]
4 FUNCTION
32
4.7 Simple Two-degree-of-freedom
Set value (SV) change point
Fast
Normal
Slow
Time