Rockwell Automation 1769-SM2 Compact I/O DSI/Modbus Communication Module - Manual (Page 57)

Configuring the Module 3-19
Figure 3.20 Example RTU Tx Delay HIM Screen for CH1 Drives
2. Reset the module (see Resetting the Module on page 3-20 ).
Setting the RTU Message Timeout
1. Set the values of Parameters 18 - [RTU MsgTimeout 1], 33- [RTU
MsgTimeout 2], and 48 - [RTU MsgTimeout 3] to establish the
amount of time that the module will wait for a response from the
respective channel’s drives.
Figure 3.21 Example RTU MsgTimeout HIM Screen for CH1 Drives
Important: The RTU Message Timeout value must be considered
when determining the timeout values in the slave nodes.
For example, if five RTU messages are being sent to a
slave node and the slave is powered down, the overall
network cycle time can increase by as much as 10
seconds (5 messages x 2 seconds timeout for each slave
node).
2. Reset the module (see Resetting the Module on page 3-20 ).
Default: 0 milliseconds
Minimum: 0 milliseconds
Maximum: 500 milliseconds
RTU Tx Delay 1
Parameter: # 017
0
VALUE LIMITS SEL
TIP: If the Modbus RTU slave is a PowerFlex 4-Class drive, set the
value of [RTU Tx Delay x] to 8 milliseconds when the value of
[RTU Baud Rate x] is 19200.
Default: 2 seconds
Minimum: 0 seconds
Maximum: 60 seconds
RTU MsgTimeout 1
Parameter: # 018
2
VALUE LIMITS SEL
TIP: When configured for RTU Master operation, the RTU Slave
addresses do not get assigned with parameter values. The Slave
address is contained in the message data as described in
Chapter 5 .