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
BISYNC Point-To-Point Protocol
Envoy Application Programming Manual—427159-001
3-17
Line Action by Procedure Call
Line Action by Procedure Call
This subsection describes the line action of the following procedures.
•
READ Procedure on page 3-17
•
WRITE Procedure on page 3-22
•
WRITEREAD Procedure (Limited Conversational Exchange) on page 3-25
•
CONTROL Procedure (Send EOT) on page 3-31
•
CONTROL Procedure (Send WACK) on page 3-31
•
CONTROL Procedure (Enable RVI) on page 3-31
•
CONTROL Procedure (Send TTD) on page 3-32
It includes the following subjects:
•
BISYNC control sequences transmitted in response to file-system procedures
•
Action of file-system procedures in response to line states
•
Reception of selected control sequences
READ Procedure
The READ procedure is used for several data communications functions, which are
described in this subsection. The possible completions of this procedure differ
depending upon the state of the Envoy line when the READ is issued.
Initial READ (Line in CONTROL State)
An initial READ (Example 3-1) causes Envoy, on behalf of the application process, to
wait for a line bid from the remote station. If a line bid is received, Envoy acknowledges
the line bid, receives the initial message, and returns the message to the buffer of the
application process. The successful receipt of the initial message is indicated by a
condition code of CCE upon completion of the READ. Following the receipt of the
initial message, the line is in the READ state.