Output Deviation For Pid Control - Hitachi SJ100 Instruction Manual

Output Deviation for PID Control

The PID loop error is defined as the
magnitude (absolute value) of the differ-
ence between the Setpoint (target value)
and the Process Variable (actual value).
When the error magnitude exceeds the
preset value for C_44, the [OD] terminal
signal turns ON. Refer to
Operation" on page
Option Terminal
Code Symbol
04 OD Output Deviation for
PID Control
11, 12, AL0 – AL2
Valid for outputs:
C_44
Required settings:
Notes:
•
The default difference value is set to 3%. To change
this value, change parameter C_44 (deviation
level).
NOTE: The example circuit in the table above 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.
"PID Loop
4–39.
Output
Function Name
State
ON
OFF
SJ100 Inverter
SP, PV
C 44
C 44
[OD] 1
ON
0
Signal
Description
when PID error is more than the set threshold for
the deviation signal
when PID error is less than the set threshold for
the deviation signal
Example (requires output configuration—
see page 3–38):
Inverter output
terminal circuit
H O OI L FM CM2
+
See I/O specs on page 4–6.
4–29
Process variable
Setpoint
ON
t
OD
12 11
RY
–