Hitachi CP-X200 instruction manual －43, Output Deviation for PID Control

4－43

443

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.

SP,PV

C044

C044

[OD] 1 signal 0

Process variable

Setpoint

ON ON

t

Option	Terminal	Function Name	State	Description
Code	Symbol
04	OD	Output Deviation for	ON	when PID error is more than the set threshold for
		PID Control		the deviation signal.
			OFF	when PID error is less than the set threshold for
				the deviation signal

Valid for inputs:	11, AL0 – AL2
Required settings	C044

Notes:

ξThe default difference value is set to 3%. To change this value, change parameter C044 (deviation level).

ξThe 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):

Inverter output
terminal circuit		OD
	CM2		11

RY

Example for terminal [AL0], [AL1], [AL2] (requires output configuration – see page 4-35 and 3-54):

Inverter logic		OD
circuit board
	AL0	AL1	AL2
	Power		Load
	supply

Monitoring	Operationsand
Monitoring	Operationsand

See I/O specs on page 4-6