Rockwell Automation 1769-SM2 Compact I/O DSI/Modbus Communication Module - Manual (Page 70)

5-6 Understanding Explicit Messaging
The RSLogix 500 Message Configuration example screen to write to a
parameter is shown in
Figure 5.4 . It is assumed that the 1769-SM2
module occupies slot 1 and is operated in Single mode, and that the drive
is connected to CH1.
See Table 5.A for descriptions of the message configuration data.
Figure 5.4 RSLogix 500 Example Message Setup Screen to Write to a Parameter
The request data for the message is stored at Data Table Address N7:2.
The Size in Bytes of the request data is 2 bytes because the data size for
PowerFlex 40 drive Parameter 78 - [Jog Frequency] is 2 bytes (1
word). No Data Table Address is specified for the response data, since
the Write Parameter service has no response data.