Hitachi SJ300 Series Interface, Operation, Three-wire

4–29

SJ300 Inverter

Three-wire

Interface

Operation

The 3-wire interface is an industry standard motor control interface. This function uses two inputs for momentary contact start/stop control, and a third for selecting forward or reverse direction. To implement the 3-wire interface, assign 20 [STA] (Start), 21 [STP] (Stop), and 22 [F/R] (Forward/Reverse) to three of the intelligent input terminals. Use momentary contact for Start and Stop. Use a selector switch, such as SPST for the Forward/Reverse input. Be sure to set the operation command selection A002=01 for input terminal control of motor.

If you have a motor control interface that needs logic-level control (rather than momentary pulse control), use the [FW] and [RV] inputs instead.

Opt.

Symbol

Function Name

Input

Description

Code

State

20

STA

Start Motor

ON

Start motor rotation on momentary

contact (uses acceleration profile)

OFF

No change to motor operation

21

STP

Stop Motor

ON

No change to motor operation

OFF

Stop motor rotation on momentary contact

(uses deceleration profile)

22

F/R

Forward/Reverse

ON

Select reverse direction of rotation

OFF

Select forward direction of rotation

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

A002=01

see page 4–12.)

STP

settings:

F/R

STA

Notes:

TH

FW

8

CM1

5

3

1

• The STP logic is inverted. Normally the

P24

PLC

CM1

7

6

4

2

switch will be closed, so you open the switch

to stop. In this way, a broken wire causes the

motor to stop automatically (safe design).

• When you configure the inverter for 3-wire interface control, the dedicated [FW] terminal is automatically disabled. The [RV] intelligent terminal assignment is also disabled.

See I/O specs on page 4–9.

The diagram below shows the use of 3-wire control. STA (Start Motor) is an edge-sensitive input; an OFF-to-ON transition gives the Start command. The control of direction is level- sensitive, and the direction may be changed at any time. STP (Stop Motor) is also a level- sensitive input.

[STA] terminal

[STP] terminal

[F/R] terminal

Motor revolution speed Forward

Reverse

Operations Monitoring and

t