6100 MPS-B Programming Manual

INTRODUCTION TO 6100 MPS-B
Station Types
In case of an unsuccessful select operation, an EOT should be
issued to terminate the operation. The application process can
issue an explicit EOT, or the next poll/select sequence can begin
with an EOT.
Fast Select. 6100 MPS-B may select one or more tributary
stations by sending a selection sequence not terminated with ENQ.
In this case, it could optionally proceed immediately to the
message transfer operation without waiting for a response. The
option depends on the type of WRITE request selected by the
application.
NOTE
The Burroughs Multipoint protocol and the ADM-2 Multipoint
protocol use two different names for Fast Select when
selecting a group of stations--sequential and broadcast.
Polling
As the supervisory station, 6100 MPS-B sends a polling sequence
terminated with ENQ to a single tributary station. The tributary
station, when it is polled, accepts master status and responds
with a message, or with EOT to indicate that it has no message,
and gives up master status.
If the message received is invalid, 6100 MPS-B sends a negative
acknowledgement (EOT as suggested in the ANSI X3.28/2.5
Standard). The tributary station will retry the message
transmission until either a valid message is received by 6100
MPS-B or the retry count specified for the line is exhausted.
If no message is received, a timeout error occurs.
In case of an unsuccessful polling operation, an EOT should be
issued to terminate the operation. The application process can
issue an explicit EOT, or the next poll/select sequence can begin
with an EOT.
NOTE
The polling sequence includes a prefix which specifies a
tributary station address. The prefix may include other
information. The ADM-2 Multipoint protocol uses the Send
Function to poll specific data from a tributary station.
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