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
Asynchronous Line Supervisor Protocol
Envoy Application Programming Manual—427159-001
10-6
Selecting by an Asynchronous Supervisor
Selecting by an Asynchronous Supervisor
An application process acting as a supervisor station initiates selecting by using the
WRITEREAD procedure to send a select sequence and to accept the response.of the
addressed terminal (Figure 10-2
).
Note. Only an asynchronous supervisor can address specific terminals through the polling and
selecting procedures. A read-only line cannot use these procedures.
Figure 10-2. Asynchronous Line Supervisor Selection
055CDT .CDD
2
Yes
CALL WRITE...
Application Checks
Response
Is
Response
Valid?
Yes
Format Message
Any
Response?
No
Timeout Completes Error = 171
Invalid Response is
Handled by the
Application
No
1
Go to Polling
Sequence
CALL WRITEREAD
(Select Sequence)
Send Select
Sequence
Send Data to
Terminal