Mitsubishi Electric FR-A800, Instruction Manual

Page: 704 / 1042

(A) Application parameters Parameters
5 - 524
5.14.9 PID control
Process control such as flow rate, air volume or pressure are possible on the inverter.
A feedback system can be configured and PID control can be performed using the terminal 2 input
signal or parameter setting value as the set point, and the terminal 4 input signal as the feedback val-
ue.
Pr. Name
Initial
value
Setting range Description
127
A612
PID control automatic
switchover frequency
9999
0 to 590 Hz
Set the value at which control is automatically
switched to PID control.
9999 Without PID control automatic switchover function
128
A610
PID action selection 0
0, 10, 11, 20, 21,
50, 51, 60, 61, 70,
71, 80, 81, 90, 91,
100, 101, 1000,
1001, 1010,
1011, 2000,
2001, 2010,
2011
Select how to input the deviation value, measured
value and set point, and forward and reverse action.
40 to 43 Refer to page 5-552
129
A613
PID proportional band 100%
0.1 to 1000%
If a narrow proportional band is set (small parameter
setting value), the manipulated amount changes
considerably by slight changes in the measured
value. As a result, response improves as the
proportional band becomes narrower, though
stability worsens as shown by the occurrence of
hunting. Gain Kp=1/proportional band
9999 Without proportional band
130
A614
PID integral time 1 s
0.1 to 3600 s
With deviation step input, this is the time (Ti) used for
obtaining the same manipulated amount as
proportional band (P) by only integral (I) action.
Arrival to the set point becomes quicker the shorter
an integral time is set, though hunting is more likely
to occur.
9999 Without integral control
131
A601
PID upper limit 9999
0 to 100%
Sets the upper limit. The FUP signal is output when
the feedback value exceeds this setting. The
maximum input (20 mA/5 V/10 V) of the measured
value (terminal 4) is equivalent to 100%.
9999 No function
132
A602
PID lower limit 9999
0 to 100%
Set the lower limit. The FDN signal is output when
the measured value falls below the setting range. The
maximum input (20 mA/5 V/10 V) of the measured
value (terminal 4) is equivalent to 100%.
9999 No function
133
A611
PID action set point 9999
0 to 100% Set the set point during PID control.
9999 Set point set by Pr. 128.
134
A615
PID differential time 9999
0.01 to 10 s
With deviation ramp input, this is the time (Td) used
for obtaining the manipulated amount only by
proportional action (P). Response to changes in
deviation increase greatly as the differential time
increases.
9999 Without differential control
553
A603
PID deviation limit 9999
0 to 100%
The Y48 signal is output when the absolute value of
the deviation exceeds the deviation limit value.
9999 No function
554
A604
PID signal operation
selection
0 0 to 3, 10 to 13
The action when the upper or lower limit for a
measured value input is detected or when a limit for
the deviation is detected can be selected. The
operation for PID output suspension function can be
selected.