Hitachi SJ700-2 instruction manual PID function

Chapter 4 Explanation of Functions

4.2.23 PID function

The PID function allows you to use the inverter for the process control on fluid flow, airflow, and pressure.

To enable this function, specify "01 lenabled" or "02 inverted data output enabled" for function "A071".

You can disable the PID function with an external signal during the PID operation. For this purpose, assign function "23" (PID terminal: disabling PID operation) to an intelligent input terminal. Turning the PID terminal on disables the PID function and makes the inverter perform the normal output.

With the PID function, you can limit the PID output according to various conditions.

Refer to maximum frequency (4.2.10), frequency limiter (4.2.20), PID rariation range (A078).

Related code

A001: Frequency source setting

A005: [AT] selection

A006: [O2] selection

A071: PID Function Enable

A072: PID proportional gain

A073: PID integral time constant

A074: PID derivative gain

A075: PV scale conversion

A076: PV source setting

A077: Output of inverted PID deviation

A078: PID variation range

A079: PID feed forward selection

d004: Process variable (PV), PID feedback monitoring

C001 to C008: Terminal [1] to [8] functions

C021 to C025: Terminal [11] to [15] functions

C044: PID deviation level setting

C052: Off level of feedback comparison signal

C053: Onlevel of feedback comparison signal

Item	Function code	Data or range of data	Description
PID Function Enable	A071	00	Disabling the PID operation
		01	Enabling the PID operation
		02	Enabling inverted-data output
PID proportional gain	A072	0.2 to 5.0	Proportional gain
PID integral time constant	A073	0.0 to 3600.(s)	Integrated gain
PID derivative gain	A074	0.00 to 100.0(s)	Derivative gain
PV scale conversion	A075	0.01 to 99.99	Scale for unit conversion of PID feedback
			data
		00	OI-L: 4 to 20 mA
PV source setting	A076	01	O-L: 0 to 10 V
		02	RS485 communication
		03	Frequency command as pulse train
		10	Operation result (*1)
Output of inverted PID	A077	00	Disabling the inverted output
			Enabling the inverted output (deviation
deviation		01
			polarity inverted)
PID variation range	A078	0.0 to 100.0(%)	Range of PID data variation with
			reference to the target value
		00	Invalid
PID feed forward selection	A079	01	O-L : 0-10V
		02	OI-L : 4-20mA
		03	O2-L : -10-10V
PID deviation level setting	C044	0.0 to 100.0(%)	Level to determine the OD signal output
Off level of feedback	C052	0.0 to 100.0(%)	Level to determine the FBV signal output
comparison signal
Onlevel of feedback	C053	0.0 to 100.0(%)	Level to determine the FBV signal output
comparison signal

(*1) refer 4.2.12 Frequency operation function

(1) Basic configuration of PID control

Feed Forward

invalid

0-10V

0-20mA

-10-10V

Target value

Deviation

Operation

0 to 10 V

4 to 20 mA

(ε)

quantity

+

Kp（1+

1

+Td･S） +

Normal control

M ＝

fs

-

Ti･S

by the inverter

Feedback

0 to 10 V

Transducer

4 to 20 mA

Sensor

Kp: Proportional gain	Ti: Integral time	Td: Derivative time	s: Operator	ε: Deviation
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