6100 ADCCP Programming Manual

ADCCP-to-Token Ring Communication
ADCCP Link and Station Management
069225 Tandem Computers Incorporated 2–15
Figure 2-7. Alternate Polling
Primary
Station
Secondary
Stations
RR-P (1)
RNR-F (1)
RR-P (2)
RR-F (2)
RR-P (1)
RR-F (1)
I (1)
RR-P (2)
RR-F (2)
I (1)
RR-P (1)
RNR-F (1)
021
ADCCP-to -Token Ring
Communication
When a token ring controller receives a SNRM frame from a primary station, the
controller sends a SNRM frame to the appropriate secondary station in the token ring
and returns a DM frame to the primary station. When the controller receives a UA
frame from the secondary station in the token ring, the controller sends a UA frame to
the primary station that sent the SNRM frame. To allow the primary station enough
time to wait for the UA response from a station in the token ring, your application
must turn on Option_Two.
In Option_Two, the primary station ignores the DM frame and waits for the UA frame
until the T1TIMER expires then sends another SNRM. The primary stations retires
sending a SNRM to the number of times specified by the L2RETRY line option. Figure
2-8 shows Option_Two behavior between a primary station using ADCCP and a
secondary or combined station using a token ring controller. (Token ring is not a
station type for ADCCP.)