4-24
Chapter 4. Functions
z
PID control initialization
When changing the LSP or switching SP groups, the manipulated variable (MV)
may be stuck at the low or high limit, the PV may be resistant to change, or the PV
may overshoot. PID control initialization is effective in preventing these problems.
It can be set for each control loop.
Item (bank)
Display
Description
Initial value
PID initialization
(CONTROL bank)
MENU > Control
PID initialization
0: Automatic*
1
1: No initialization*
2
2: Initialize (if a new SP is input)*
3
0
*1. If 0 (Automatic) is set
When the LSP value is changed or SP groups are switched, whether the PID control must be initialized or not is
determined automatically, and it is initialized only when necessary.
*2. If 1 (No initialization) is set
When the LSP value is changed or SP groups are switched, the PID control is not initialized. This is a useful setting if the
continuity of the manipulated variable (MV) is important when the LSP value is changed or SP groups are switched.
*3. If 2 (Initialize) is set
PID control is always initialized when the LSP value is changed or SP groups are switched. This is a useful setting if prompt
response (increase or decrease) of the manipulated variable (MV) to the relationship between PV and SP is important
when the LSP value is changed or SP groups are switched.
z
PID initial MV
The initial output of PID control is the MV used for PID control immediately after
the loop mode is changed from READY to RUN, or after RUN mode is activated
when the power is turned on. It can be set for each control loop.
Item (bank)
Display
Description
Initial value
PID initial MV (CONTROL
bank)
MENU > Control
PID initial MV
-10.000 to +110.00%
0.0000
Handling Precautions
•
If the "Control action" is changed from a setting other than the PID control
heating/cooling action to the PID control heating/cooling action, the "PID
initial MV" is reset to 50.000 %.
•
If the "Control action" is changed from the PID control heating/cooling action
to a setting other than the PID control heating/cooling action, the "PID initial
MV" is reset to 0.0000 %.
