Rockwell Automation 1769-ADN Compact I/O 1769-ADN DeviceNet Adapter - Manual (Page 166)

Publication 1769-UM001B-EN-P - October 2002
B-8 Explicit Messaging Application Examples
The following screen is the Communications tab for the MSG
instruction above.
The reply to this message, when successful, will be one word of data
containing the word length of the configuration file for the 1769 I/O
module to which the message was sent. This data will be stored in the
Logix5550 controller at the tag specified in the “Destination” field for
the message instruction.
Set 1769 I/O Module Configuration
The length of this command is determined by the size of the
configuration file for the 1769 I/O module we will configure. In this
case, from the previous section, we read the configuration size for the
1769-OF2 as 8 words (16 bytes). Six words contain the configuration
data, while the last two words must be set to 0. The length, however,
must be 16 bytes.