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8.3.8
Simple two-degree-of-freedom
This is the simplified control form of the two-degree-of-freedom PID control. In this form of PID control, the temperature
control module controls the target subject using not only PID constants but also the control response parameter. The
response speed toward the change of the set value (SV) can be selected from three levels.
General PID control is called one-degree-of freedom PID control. In the one-degree-of freedom PID control, when PID
constants that improve "response to the change of the set value (SV)" are set, "response to the disturbance" worsens.
Conversely, when PID constants that improve "response to the disturbance" are set, "response to the change of the
set value (SV)" worsens.
On the other hand, in the two-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.
Note that required parameter settings increase and PID constants can hardly be auto-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.
The level of "response to the change of the set value (SV)" can be selected from the following, maintaining the PID
constants that improve "response to the disturbance".
• Fast
• Normal
• Slow
Temperature process value (PV)
Set value (SV) 2
Change
Set value (SV) 1
(1) Setting method
1.
Set "Method selection" to "Param write" of the control mode to be used.
"CC IE Field Configuration" windowSelect the temperature control module from "List of
stations"[CC IE Field Configuration][Online][Parameter Processing of Slave Station]
2.
Set "CH Control response parameter".
Fast
Set value (SV) change point
CHAPTER 8 FUNCTIONS
Normal
Slow
Time
Standard
Heating-cooling
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Troubleshooting
