Mitsubishi Electric FR-A700 EC, Instruction Manual

Page: 669 / 826

Parameter Special operation
FR-A700 EC 6 - 489
Pr. No. Name
Initial
Value
Setting
Range
Description Parameters referred to
Refer to
Section
127
PID control auto-
matic switchover
frequency
9999
0–400Hz
Set the frequency at which the control is
automatically changed to PID control.
59
73
79
178–189
190–196
C2 (Pr. 902)
–
C7 (Pr. 905)
Remote function
selection
Analog input
selection
Operation mode
selection
Input terminal
function selection
Output terminal
function selection
Frequency
setting voltage
(current) bias/
gain 6.10.4
6.20.2
6.22.1
6.14.1
6.14.5
6.20.5
9999
Without PID automatic switchover
function
128
PID action
selection
10
10
PID reverse
action
Output signal of an
external PID control-
ler: terminal 1
11
PID forward
action
20
PID reverse
action
Measured value
(terminal 4 )
Set point (terminal 2
or Pr. 133)
21
PID forward
action
50
PID reverse
action Deviation value signal
input
(LONWORKS , CC-
Link communication)
51
PID forward
action
60
PID reverse
action
Measured value, set
point input
(LONWORKS , CC-
Link communication)
61
PID forward
action
70
PID reverse
action
Deviation value signal
input (PLC function)
71
PID forward
action
80
PID reverse
action
Measured value, set
point input
(PLC function)
81
PID forward
action
90
PID reverse
action Deviation value signal
input (PLC function)
(Not reflected to the
inverter frequency)
91
PID forward
action
100
PID reverse
action Measured value, set
point input (PLC
function) (Not
reflected to the
inverter frequency)
101
PID forward
action
129
PID proportional
band
100%
0.1–1000%
If the proportional band is narrow
(parameter setting is small), the manip-
ulated variable varies greatly with a
slight change of the measured value.
Hence, as the proportional band nar-
rows, the response sensitivity (gain)
improves but the stability deteriorates,
e.g. hunting occurs.
Gain Kp = 1/proportional band
9999 No proportional control
130
PID integral time
1s
0.1–3600s
For deviation step input, time (Ti)
required for only the integral (I) action to
provide the same manipulated variable
as that for the proportional (P) action.
As the integral time decreases, the set
point is reached earlier but hunting
occurs more easily.
9999 No integral control.
131
PID upper limit
9999
0–100%
Set the upper limit value. If the feedback
value exceeds the setting, the FUP signal
is output. The maximum input (20mA/
5V/10V) of the measured value (terminal
4) is equivalent to 100%.
9999 No function