Rockwell Automation 1769-SM2 Compact I/O DSI/Modbus Communication Module - Manual (Page 55)

Configuring the Module 3-17
In Multi-Drive mode, any module channel can be configured for RTU
Master operation by setting Parameter 07 - [DSI I/O Cfg 1], 22 - [DSI
I/O Cfg 2] or 37 - [DSI I/O Cfg 3] to “5” (RTU Master). When doing
this, additional Modbus RTU Master parameters must be set to complete
that channel’s configuration.
Setting the RTU Baud Rate
By default, each channel set for RTU Master operation uses a 38.4K
baud rate. The values of Parameters 14 - [RTU Baud Rate 1], 29 -
[RTU Baud Rate 2], and 44 - [RTU Baud Rate 3] set the specific baud
rate used by the respective channel to communicate.
1. Set the values of Parameters 14 - [RTU Baud Rate 1], 29 - [RTU
Baud Rate 2], and 44 - [RTU Baud Rate 3] to the specific baud rate
at which that channel communicates.
Figure 3.17 Example RTU Baud Rate HIM Screen for CH1 Drives
2. Reset the module (see Resetting the Module on page 3-20 ).
Selecting the RTU Format
By default, each channel set for RTU Master operation uses an RTU
format of 8-N-1. The RTU format consists of data bits (8 data bits only),
parity (None, Even or Odd), and stop bits (1 or 2).
1. Set the values of Parameters 15 - [RTU Format 1], 30- [RTU
Format 2], and 45 - [RTU Format 3] to match the communication
format required for the respective channel.
Configuring the Modbus RTU Master Parameters
Value Baud Rate
0 38.4K bits/sec (default)
1 19200 bits/sec
2 9600 bits/sec
3 4800 bits/sec
4 2400 bits/sec
5 1200 bits/sec
6 600 bits/sec
7 300 bits/sec
RTU Baud Rate 1
Parameter: # 014
0
VALUE LIMITS SEL