Three-wire interface operation – Hitachi L2002 User Manual

Page 170

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Using Intelligent Input Terminals

Oper

ations

and Monitor

ing

4–26

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 a
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 momen-
tary pulse control), use the [FW] and [RV] inputs instead.

Option

Code

Terminal

Symbol

Function Name

Input

State

Description

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 inputs:

C001, C002, C003, C004,
C005

Required settings:

A002 = 01

Notes:

The STP logic is inverted. Normally the 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 inter-
face control, the dedicated [FW] terminal is
automatically disabled. The [RV] intelligent
terminal assignment is also disabled.

Example (requires input configuration—
see page

3–47

):

See I/O specs on page

4–6

.

STP

STA

F/R

1

2

3

4

5

L

PCS

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