
USING THE BDLC PROTOCOL
UNILINK HOST
ADAPTER B–2
USER MANUAL
B.1 BDLC CONFIGURATIONBDLC is an unbalanced configuration meaning that there is one primary
station
(the host computer) and one or more secondary stations (UNILINK Host
Adapters) as illustrated in Figure B–1. The primary is responsible for setting
each
secondary to the normal response mode and for controlling the
information
exchange.
PRIMARY
(Host Computer)
Commands
Responses
Secondary
Adapter
“A”
Secondary
Adapter
“B”
Figure B–1 BDLC Unbalanced ConfigurationIn
the normal response mode, a secondary station may only transmit frames as
a direct result of receiving permission from the primary. The primary grants
this
permission by polling the secondary stations.