User`s manual

FX3U Series Programmable Controllers

User’s Manual - MODBUS Serial Communication Edition

7 MODBUS Standard Commands

7.8 Write Single Coil (Command Code: 0x05)

Writes a value (ON/OFF) to one coil.

1) Request message format (Master → Slave)

2) Response message format (Slave → Master)

(When completed normally)

The slave returns the request message received from the master without change.

(When completed with an error)

*1. Exception and error codes are stored in special data registers and special auxiliary relays in the case

of error completion. Refer to Chapter 6 for storage location, confirmation methods, and other detailed

contents.

Data

(L) (L)

Function code

Function

code

(05

Coil number

(0000

H to FFFFH)

ON/OFF specification

0000H : OFF

FF00

H : ON

(H)

Data

Function code

Function

code

(85

Exception

code*