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
3-21
READ Procedure
Initial READ (Line in WRITE State)
An initial READ while the line is in the WRITE state (Example 3-4) causes Envoy, on
behalf of the application process, to send an EOT sequence to the remote station. This is
the normal method for terminating a transmission to a remote station. Following the
transmission of the EOT sequence, the action taken is the same as that for an initial
READ from the CONTROL state (that is, the local station waits for a line bid from the
remote station).
The file-system errors applicable to an initial READ from the CONTROL state are also
applicable for an initial READ from the WRITE state.
Initial READ of ID (Line in CONTROL State)
If an ID exchange is to take place, the line must first be configured for ID exchange
when issuing the ADD DEVICE command or with a call to the SETMODE procedure.
An initial READ (Example 3-5
) causes Envoy, on behalf of the application process, to
wait for a line bid from the remote station. The receipt of the ID ENQ sequence is
indicated by a condition code of CCE upon completion of the READ. The message and
the ID are returned to the buffer of the application process. Following the receipt of the
ID sequence, the line is in the DISCONNECT state.
172 Reply not proper for protocol. The data received while
waiting for a line bid or for text was not proper for the
BISYNC protocol.
CONTROL
173 Transmission error. The message received was in error and a
NAK sequence was sent the number of times specified by the
retry value.
CONTROL
177 Text overrun. The length of the message received exceeds the
length specified in the read count parameter. The READ was
attempted the number of times specified by the retry value.
CONTROL
Example 3-4. Initial READ (Line in WRITE State)
Local Remote
line state = WRITE
CALL READ(...)
|
| EOT -->
v
Table 3-11. Errors on Continuation READ for BISYNC Point-to-
Point (page 2 of 2)
Error
Number Description
Resultant Line
State