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Laurel Electronics LTE SERIES TRANSMITTERS PULSE INPUT User Manual

Page 31

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5.0 SUPPORTED EXCEPTION RESPONSE CODES

Code

Name

Error Description

---- -------------------- ------------------------------------------------------
01

Illegal Function

Illegal Function Code for this Slave. Only hex Function

Codes 03, 04, 05, 08, 10 (dec 16) are allowed.

02

Illegal Data Address Illegal Register Address for this Slave.

03

Illegal Data Value Illegal data value or data length for the Modbus protocol.

04

Slave Device Failure Slave device failure (eg. Transmitter set for external gate).

6.0 MESSAGE FORMATTING

MA = Meter Address

DD = Data (Hex)

CL = CRC Lo Byte

FC = Function Code

WW = Data (On/Off)

CH = CRC Hi Byte

RA = Register Address

SF = Sub-Function

CR = Carriage Return

NR = Number of Registers

EC = Error Code

LF = Line Feed

NB = Number of bytes

LRC = ASCII Checksum

Modbus RTU Format

Byte Number

FC

Action

> 3.5

Char

1

2

3

4

5

6

7

8

9

10

11

03
03

Request
Response

NoTx
NoTx

MA
MA

FC
FC

RA
NB

RA

DD*

NR

DD*

NR

CL

CL

CH

CH

04
04

Request
Response

NoTx
NoTx

MA
MA

FC
FC

RA
NB

RA

DD*

NR

DD*

NR

CL

CL

CH

CH

05
05

Request
Response

NoTx
NoTx

MA
MA

FC
FC

RA
RA

RA
RA

WW
WW

WW
WW

CL
CL

CH
CH

08
08

Request
Response

NoTx
NoTx

MA
MA

FC
FC

SF
SF

SF
SF

WW

DD

WW

DD

CL
CL

CH
CH

10
10

Request
Response

NoTx
NoTx

MA
MA

FC
FC

RA
RA

RA
RA

NR
NR

NR
NR

NB

CL

DD*

CH

DD* CL CH

Exception

Response

NoTx

MA FC

+80

EC

CL CH

DD* = (DD DD) times NR (Number of Registers)