Mitsubishi FR-F720-00046-NA Instruction Manual page 286

PID control
⋅ Take caution when the following condition is satisfied because the inverter recognizes the deviation value as a
negative (positive) value even though a positive (negative) deviation is given:
Pr. 934 PID display bias coefficient
To perform a reverse operation, set the forward operation in Pr. 128 PID action selection. To perform a forward
operation, set the reverse operation in Pr. 128. In this case, the PID output shutoff release level is (1000 - Pr. 577).
Pr. 934 < Pr. 935 (normal setting)
Reverse operation
Forward operation
PID output shutoff release
level
(Example) Set the following: Pr. 934 = "500" and
20% (4mA is applied), Pr. 935 = "100"
and 100% (20mA is applied).
When the set point=400 and the
measured value=360, the deviation is
+40 (>0), but the inverter recognizes the
deviation with -10% (<0). Because of
this, operation
increase
setting.
The operation amount increases when
the forward operation is set.
To perform PID output shutoff release at
deviation of +40 or higher, set Pr. 577 =
"960."
(2) Analog input display unit changing (Pr. 241)
⋅ You can change the analog input display unit (%/V, mA) for analog input bias/gain calibration.
⋅ Depending on the terminal input specification set to Pr. 73, Pr. 267, and voltage/current input switch the display units
of C3(Pr. 902), C4(Pr. 903), C43(Pr. 934), C45(Pr. 935) change as shown below.
Analog Command (Terminal 4)
(according to Pr. 73, Pr. 267, and Voltage/Current
Input Switch)
0 to 5V input
0 to 10V input
4 to 20mA input
276
> Pr. 935 PID display gain coefficient
Reverse operation
setting to Pr. 128
Forward operation
setting to Pr. 128
Pr. 577 - 1000
amount does
in the reverse operation
0 to 5V →
displayed in 0 to 100%(0.1%).
0 to 10V →
displayed in 0 to 100%(0.1%).
0 to 20mA →
displayed in 0 to 100%(0.1%).
Pr. 934
Reverse operation
Forward operation
PID output shutoff release
level
Set point
Deviation +40
Measured value
not
Pr. 241 = 0 (Initial Value)
≥ Pr. 935
Forward operation
setting to Pr. 128
Reverse operation
setting to Pr. 128
1000 - Pr. 577
500
400
360
100
0
20%
(0%) (25%)(35%)
↓
Deviation -10%
* ( ) indicates the deviation value
which the inverter can
recognize
Pr. 241 = 1
0 to 100% →
displayed in 0 to 5V(0.01V).
0 to 100% →
displayed in 0 to 10V(0.01V).
0 to 100% →
displayed in 0 to 20mA(0.01mA).
100%
(100%)