Rockwell Automation 1747-KE,D17476.12 DH-485/RS-232C Interface Module - Manual (Page 31)

Publication 1747-UM005B-EN-P - March 2006
Communicate with the Interface Module 3-5
Messages from the remote nodes on the DH-485 network (such as the
SLC nodes) use the destination address of the module. Normally the
module responds to a message from the DF1 master by swapping the
source and destination addresses in the received message, assuring
that the reply message is sent to the proper DF1 master station.
If a DH-485 node initiates a message to the DF1 master, the module
overwrites the destination address with the master station value
configured in the Remote mode submenu. The message received by
the half-duplex master will contain a source address equal to the
station address specified in the poll packet, and a destination address
equal to the address of the half-duplex master device.
Remember that half-duplex DF1 (group) addresses are in octal and
DH-485 node addresses are in decimal.
The table on page 3-6 provides the conversion using the group
number.