Output Deviation For Pid Control - Hitachi WJ200 Series Instruction Manual

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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 Terminal
Code Symbol
OD
04
Valid for inputs:
Required settings
Notes:
• The default difference value is set to 3%. To
change this value, change parameter
(deviation level).
• 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.
Function Name State
Output Deviation for
PID Control
11, 12, AL0 – AL2
C044
C044
SP,PV
C044
C044
[OD] 1
signal
0
ON when PID error is more than the set threshold for
the deviation signal.
OFF when PID error is less than the set threshold for the
deviation signal
Example for terminal [11] (default output
configuration shown – see
Inverter output
terminal circuit
Example for terminal [AL0], [AL1], [AL2] (requires
output configuration – see
Inverter logic
circuit board
See I/O specs on
Process variable
Setpoint
ON ON
Description
page 3-90):
OD
CM2 11
RY
page 4-52 and
OD
AL0 AL1 AL2
Power
Load
supply
page 4-6
t
3-90):