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
3-41
WRITEREAD Operation
WRITEREAD Operation
The normal WRITEREAD operation acts as if a WRITE were followed immediately by
a READ. Figure 3-9
shows the action of the local station in response to line conditions
on a multileaving conversational WRITEREAD.
Note. The SWIFT protocol has a fixed value for retry count of 30 for the WACK ENQ
sequence.
Figure 3-9. BISYNC Point-to-Point Multileaving WRITEREAD
021CDT .CDD
Send Text
EOT SOH
ENQ DLE
ACK0 NAK
CALL
WRITEREAD...
No
No
Wait for Response
Drop
DTR *
Error
= 163
NAK?
No
Timeout?
Yes
Yes
Transmission
Error?
Yes
Message or
Correct ACK?
ENQ Recd?
RVI Recd?
Yes
Retry
Count = 0?
Error
= 172
EOT Recd?
Protocol
Error?
Error
= 164
Error
= 175
Retry
Count = 0?
Error
= 168
Text With
Error?
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
Yes
No
No
Yes
*Data Terminal Ready if Switched Line
Text Overrun?
Yes
Retry
Count = 0?
Error
= 177
Yes
No
Retry
Count = 0?
Error
= 173
Retry
Count = 0?
Error
= 162
Yes
Yes
No
Retry
Count = 0?
Error
= 162
Yes
No
No
No
No
DLE EOT
Recd?
Error
= 0