MODEL: R7M

R7M SPECIFICATIONS

ES-7803 Rev.26 Page 6/39

http://www.m-system.co.jp/

MODBUS FUNCTION CODES & SUPPORTED CODES

■ Data and Control Functions

CODE

NAME

01

Read Coil Status

Digital output from the slave

（read/write）

02

Read Input Status

Status of digital inputs to the slave

（read only）

03

Read Holding Registers

General purpose register within the slave

（read/write）

04

Read Input Registers

Collected data from the

eld by the slave

（read only）

05

Force Single Coil

Digital output from the slave

（read/write）

06

Preset Single Register

General purpose register within the slave

（read/write）

08

Diagnostics

11

Fetch Comm. Event Counter

Fetch a status word and an event counter

12

Fetch Comm. Event Log

A status word, an event counter, a message count and a eld of event bytes

15

Force Multiple Coils

Digital output from the slave

（read/write）

16

Preset Multiple Registers

General purpose register within the slave

（read/write）

17

Report Slave ID

Slave type

/ ‘RUN’status

■ Exception Codes

CODE

NAME

01

Illegal Function

Function code is not allowable for the slave

02

Illegal Data Address

Address is not available within the slave

03

Illegal Data Value

Data is not valid for the function

■ Diagnostic Subfunctions

CODE

NAME

00

Return Query Data

Loop back test

MODBUS I/O ASSIGNMENT

ADDRESS

DATA TYPE

DATA

Coil (0X)

1 – 16

Digital Output (discrete output of the basic module)

17 – 32

Digital Output (discrete output of the extension module)

Inputs (1X)

1 – 16

Digital Input (discrete input of the basic module)

17 – 32

Digital Input (discrete input of the extension module)

33 – 48

Reserved (unused)

49 – 64

Module Status

65 – 80

Reserved (unused)

Input Registers (3X)

1 – 4

I

Analog Input

5 – 16

----

Reserved (unused)

17 – 24

F

Analog Input

25 – 48

----

Reserved (unused)

Holding Registers (4X)

1 – 2

I

Analog Output

3 – 16

----

Reserved (unused)

17 – 20

F

Analog Output

21 – 48

----

Reserved (unused)

I : Integer, -1500 – +11500 (-15 – +115%)

F : Floating

Note: DO NOT access addresses other than mentioned above. Such access may cause problems such as inadequate operation.