Envoy Application Programming Manual
Table Of Contents
- What’s New in This Manual
- About This Manual
- 1 Application Programming With Envoy
- 7 ADM-2 Multipoint Supervisor Protocol
- 8 TINET Multipoint Supervisor Protocol
- 9 Burroughs Point-To-Point Protocol
- 10 Asynchronous Line Supervisor Protocol
- A ASCII Character Set
- B ASCII to EBCDIC Code Conversion
- C File-System Procedures
- D Statistics Messages
- E S-Series Changes to Envoy
- NonStop™ Himalaya S-Series Server Architecture
- G-Series Migration Considerations
- CBSENSEON and CFSENSEON Modifiers
- LEOTRESYN and NOLEOTRESYN Modifiers
- Treatment of Characters After the Termination Character
- Number of SYN Characters
- DTR Drop
- Reporting of Parity Error
- Half-Duplex Support for Asynchronous Lines
- Controller Replacement
- SYSGEN and COUP
- Unit Numbers
- FDX Line Changes
- No Support for Auto-Call Unit
- Glossary
- Index
ADM-2 Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
7-11
Polling Type
•
Nonresponding Terminal List on page 7-17
Polling Type
The ADM-2 multipoint supervisor protocol supports the following types of polling:
•
Continuous Polling on page 7-11
•
Noncontinuous Polling on page 7-12
•
Specific Polling on page 7-14
Continuous Polling
Continuous polling occurs indefinitely until a terminal responds to the poll with text or
an error occurs. Continuous polling is specified through the poll type parameter of the
DEFINELIST procedure or the function parameter of the CHANGELIST procedure.
Envoy always keeps track of the last terminal polled. The first terminal polled when
polling is initiated is the one indicated by the next entry in the poll list (the first terminal
to be polled when the line is opened is the one indicated by the first entry in the poll
list). If a polled terminal responds with an EOT, the next terminal in the poll list is
polled. If a pass has been made through the poll list (that is, all terminals in the list have
been polled once), and another pass through the poll list is indicated, the polling
sequence continues. Figure 7-3
shows a continuous poll sequence.
Figure 7-3. ADM-2 Multipoint Supervisor Continuous Poll Sequence
044CDT .CDD
CALL READ...
CALL OPEN...
CALL DEFINELIST...
Poll List Entry
pn-1
Poll List Entry 0
Poll List Entry 1
EOT
EOT
EOT