Hitachi SJ300 Series PID ON/OFF and PID Clear

4–30

Using Intelligent Input Terminals

PID ON/OFF and PID Clear

The PID loop function is useful for controlling motor speed to achieve constant flow, pressure, temperature, etc. in many process applications. The PID Disable function temporarily suspends PID loop execution via an intelligent input terminal. It overrides the parameter A071 (PID Enable) to stop PID execution and return to normal motor frequency output characteristics. the use of PID Disable on an intelligent input terminal is optional. Of course, any use of the PID loop control requires setting PID Enable function A071=01.

The PID Clear function forces the PID loop integrator sum = 0. So, when you turn ON an intelligent input configured as [PIDC], the integrator sum is reset to zero. This is useful when switching from manual control to PID loop control and the motor is stopped.

CAUTION: Be careful not to turn PID Clear ON and reset the integrator sum when the inverter is in Run Mode (output to motor is ON). Otherwise, this could cause the motor to decelerate rapidly, resulting in a trip.

Operations and Monitoring

Opt.

Symbol

Function Name

Input

Description

Code

State

23

PID

PID Disable

ON

Disables PID loop execution

OFF

Allows PID loop execution if A71=01

24

PIDC

PID Clear

ON

Force the value of the integrator to zero

OFF

No change to PID loop execution

Valid for

C001, C002, C003, C004,

Example: (Requires input configuration—

inputs:

C005, C006, C007, C008

see page 3–47. Jumper position shown is

for –xFU/-xFR models; for –xFE models,

Required

A071

see page 4–12.)

PID

settings:

PIDC

Notes:

TH

FW

8

CM1

5

3

1

• The use of [PID] and [PIDC] terminals are

P24

PLC

CM1

7

6

4

2

optional. Use A071=01 if you want PID loop

control enabled all the time.

•Do not enable/disable PID control while the

motor is running (inverter is in Run Mode).

• Do not turn ON the [PIDC] input while the motor is running (inverter is in Run Mode).

See I/O specs on page 4–9.