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
3-1
3
BISYNC Point-To-Point Protocol
The BISYNC point-to-point protocol allows an application process to act as a station in
a binary synchronous (BISYNC) point-to-point network.
One of the implementations of this protocol is for a Computer Based Terminal (CBT) in
the Society for Worldwide Interbank Financial Telecommunications (SWIFT) network.
There are some special considerations for the Envoy-SWIFT implementation, which are
described in this section.
Topics discussed in this section include:
•
Protocol Capabilities on page 3-1
•
Application Process Interface on page 3-4
•
File-System Procedures on page 3-8
•
Message Formats on page 3-11
•
File-System Errors on page 3-16
•
Line Action by Procedure Call on page 3-17
•
Line-Error Handling on page 3-32
•
Programming Examples on page 3-42
Protocol Capabilities
Point-to-point BISYNC lines operate in contention mode, that is, neither station has total
control of the line. A station sending data normally gains control of the line by issuing a
line bid (ENQ) and by receiving a positive response (ACK) from the other station. With
the multileaving option, the two stations mutually exchange synchronization requests.
This subsection includes:
•
Exceptions to BISYNC Standard on page 3-1
•
Envoy BISYNC Features on page 3-2
•
Envoy-SWIFT Considerations on page 3-3
Exceptions to BISYNC Standard
With the following exceptions, the Envoy BISYNC point-to-point protocol conforms to
the Binary Synchronous Communication point-to-point standard as described in the
manual IBM General Information—Binary Synchronous Communications (Order No.
GA27-3004). Unlike the standard, Envoy:
•
Supports conversational multileaving
•
Allows the user to set the retry counts