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
Envoy Application Programming Manual—427159-001
4-1
4
BISYNC Centralized Multipoint
Supervisor Protocol
The BISYNC centralized multipoint supervisor protocol allows a network consisting of
two or more stations to communicate over a leased multidrop line. One station is
designated as the supervisor and the other stations are designated as tributaries.
This section describes the binary synchronous communication protocol used by an
application process acting as a supervisor station in a BISYNC centralized multipoint
network. The supervisor controls all communications within the network.
Topics discussed in this section include:
•
Protocol Capabilities
•
Application Process Interface
•
File-System Procedures
•
Address-List Format
•
Polling
•
Message Formats
•
File-System Errors
•
Line Action by Procedure Call
•
Line-Error Handling
•
Programming Examples on page 4-44
Protocol Capabilities
The Envoy BISYNC multipoint supervisor protocol conforms to the binary synchronous
communication standard described in IBM document number GA27-3004-2 for
centralized multipoint communication. The protocol offers the following capabilities:
•
ASCII or EBCDIC line code
•
Check-character generation and verification performed by the Envoy hardware.
Envoy performs automatic retries of operations that are in error.
•
Data-link control using established data link control character sequences
•
Timeouts on all line operations (according to established BISYNC standards)
•
Limited conversational mode
•
A variety of heading and message formats (Table 4-1).