User guide
Communicating through the 1785KA5
Communication Adapter Module
Chapter 3
3-6
This section explains:
gateway mode addressing
how the 1785-KA5 operates as a gateway
“single-hop” mode packets
Gateway Mode Addressing
All DH+ and DH485 destination and source addresses are contained in the
lower address byte, leaving the upper byte free for “sub-addressing.” An
internet device sends a packet to a non-internet device on the DH485 link
by:
addressing the lower byte of the STATION address (D_STATION[0]) to
the 1785-KA5 adapter module for packet processing
addressing the upper byte of the STATION address (D_STATION[1]) to
the actual destination device. The upper byte of the STATION field is
defined as follows:
1785KA5
Gateway
Communication