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XLT Hitachi X200 User Manual

Page 192

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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

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