Output Deviation for PID Control
The PID loop error is defined as the
magnitude (absolute value) of the difference
between the Setpoint (target value) and the
Process Variable (actual value). When the
error magnitude exceeds the preset value
for C044, the [OD] terminal signal turns ON.
Refer to
“PID Loop Operation” on page 4–
56.
Option
Code
Terminal
Symbol
Function Name
State
Description
ON
when PID error is more than the set threshold for
the deviation signal.
04
OD
Output Deviation for
PID Control
OFF
when PID error is less than the set threshold for
the deviation signal
Valid for inputs:
11, AL0 – AL2
Required settings
C044
Notes:
x
The default difference value is set to 3%. To
change this value, change parameter C044
(deviation level).
x
The example circuit for terminal [11] drives a
relay coil. Note the use of a diode to prevent the
negative-going turn-off spike generated by the
coil from damaging the inverter’s output
transistor.
Example for terminal [11] (default output
configuration shown – see
page 3-54
):
Example for terminal [AL0], [AL1], [AL2] (requires
output configuration – see
page 4-35 and 3-54
):
See I/O specs on
page 4-6
RY
Inverter output
terminal circuit
CM2
11
OD
AL1
Power
supply
Load
AL0
AL2
Inverter logic
circuit board
OD
t
SP,PV
Setpoint
C044
C044
0
1
[OD]
signal
ON
ON
Process variable
4
43
Operations and
Monitori
ng
4
−
43
Operations and
Monitoring
