User`s guide

34 DC 900-1317J
ADCCP NRM Programmer’s Guide
defined. Although the configuration is symmetric, link communications may not be.
The link between one primary station and its secondary station may be established,
whereas the other primary/secondary link is not.
2.4 Frame Addressing
Frame addressing in the ADCCP protocol requires that each combined or secondary
station have a unique address. Primary stations use the address of a secondary station to
designate the destination of each transmitted command.
In a balanced configuration, each combined station has its own address. This is consis-
tent with the analogy that combined stations behave much as if each contains a primary
station that exchanges control and information with a secondary station in the other
combined station.
The result is that exchange of information between two combined stations requires two
distinct addresses. In Figure 2–2, each command/response pair constitutes a dialog
Figure 2–3: Symmetric Configuration
Station A Commands
Station B Responses
Station D Commands
Station C Responses
DRWG-0528
Local
Primary
Station
A
Local
Secondary
Station
C
Remote
Primary
Station
D
Remote
Secondary
Station
B