Simple Two-Degree-Of-Freedom - Mitsubishi Electric MELSEC iQ-R Series User Manual

1.16

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 disturbance" degrades.
Conversely, when PID constants to improve "response to the disturbance" 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
disturbance" can be compatible with each other in the two-degree-of-freedom PID control.
Note that required parameter settings increase and PID constants can hardly be automatically set by the auto tuning function
for complete two-degree-of-freedom PID control. Therefore, 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, a form that allows users to use PID
constants making good "response to the change of the set value (SV)" and "response to the disturbance" 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 setting as follows:
[Navigation window]  [Parameter]  Target module  [Application Setting]  [Control basic parameters]  [Control
Response Parameters]
1 FUNCTIONS
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1.16 Simple Two-degree-of-freedom
Fast
Set value (SV) change point
Normal
Slow
Time