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ProSoft Technology MVI69E-MBS User Manual

Page 130

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Reference

MVI69E-MBS ♦ CompactLogix Platform

User Manual

Communication Module

Page 130 of 162

ProSoft Technology, Inc.

January 6, 2014

Func Code - Tells the Master to read the register values from the Slave. FC3.

Addr in Dev - Tells the Master where in the Slave's database to obtain the data.

In the above example, the Master's Modbus command to transmit inside the
Modbus packet is as follows.

Slave address Function Code Address in Device Reg count

DEC

01

3

6100

2

HEX

01

03

17 D4

00 02

In the above example the (Enron/Daniel supporting) Slave's Modbus command to
transmit inside the Modbus packet is as follows.

Slave address Function Code Byte Count

Data

DEC

01

3

8

32.75 275.69

HEX

01

03

08

00 00 42 03 D8 52 43 89

In the above example the (a NON-Enron/Daniel supporting) Slave's Modbus
command that is transmitted inside the Modbus packet is as follows.

Slave address Function Code Byte Count

Data

DEC

01

3

4

32.75

HEX

01

03

04

00 00 42 03