Mitsubishi Electric FR-F500 Instruction Manual page 139

( 5 ) Parameter setting
Parameter
Setting
Number
10
11
128
20
21
0.1 to 1000%
129
9999
0.1 to 3600 s
130
9999
0 to 100%
131
9999
0 to 100%
132
9999
133 0 to 100%
0.01 to 10.00 s
134
9999
( 6 ) Adjustment procedure
Name
For heating, pressure control,
etc.
For cooling, etc.
PID action
selection
For heating, pressure control,
etc.
For cooling, etc.
If the proportional band is narrow (parameter setting is small), the
manipulated variable varies greatly with a slight change of the process value.
Hence, as the proportional band narrows, the response sensitivity (gain)
PID proportional
improves but the stability deteriorates, e.g. hunting occurs.
band
Gain Kp = 1/proportional band
Time required for the integral (I) action to provide the same manipulated
variable as that for the proportional (P) action. As the integral time decreases,
PID integral time
the set point is reached earlier but hunting occurs more easily.
Set the upper limit. If the feedback value exceeds the setting, the FUP signal
Upper limit is output. (Process value of 4mA is equivalent to 0% and 20mA to 100%.)
Set the lower limit. (If the process value goes out of the setting range, an
alarm can be output. In this case, the process value of 4mA is equivalent to
Lower limit
0% and 20mA to 100%.)
Only valid for the PU command in the PU operation or PU/external combined
PID action set
mode.
point for PU
For external operation, the voltage across 2-5 is the set point.
operation
(Pr. 902 value is equivalent to 0% and Pr. 903 value to 100%.)
Time only required for the differential (D) action to provide the same process
PID differential value as that for the proportional (P) action. As the differential time increases,
time greater response is made to a deviation change.
Parameter setting
Adjust the PID control parameters, Pr. 128 to Pr. 134
Set the I/O terminals and PID control terminals.
Terminal setting
Pr. 128 = 10, 11, 20, 21
Switch X14 signal on.
Run
Description
No proportional control
No integral control.
No function
No function
No differential control.
119
PARAMETERS
PID reverse
Deviation value
action
signal input
PID forward
(terminal 1)
action
PID reverse
action
Process value input
(terminal 4) PID forward
action