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
3-5
Sending EOT
Sending EOT
The sender indicates the end of a data transmission by sending an end-of-transmission
(EOT) sequence to the receiver. The application process sends the EOT sequence in
either of two ways:
•
By calling the READ procedure to monitor the line
•
By calling the CONTROL procedure to send an EOT sequence
Recognizing EOT
The receiver recognizes the end of transmission in either of two ways:
•
With a CCL condition code returned from a call to the READ procedure
•
With a file-system error 163 (EOT received) returned from a call to the FILEINFO
procedure
ASCII and EBCDIC Line Code
An application process uses only the ASCII character set. If the line code is EBCDIC,
Envoy can be configured (EBCDIC modifier) to perform the necessary ASCII-to-
EBCDIC translation. Envoy recognizes when transparent text is being transmitted and
does not translate transparent text.
Line Contention
One station on a point-to-point line is designated as the primary station and the other as
the secondary station. If both stations bid for the line simultaneously, the primary station
always takes precedence. You specify the primary and secondary designations when
issuing the ADD DEVICE command. These designations can be altered later using the
SETMODE procedure.
Retries
Line operations are subject to transmission errors in the form of BCC errors,
nonresponding remote stations, and incorrect responses from remote stations. When
errors of these types occur, Envoy retries the requested operation. You can designate the
maximum number of times that Envoy retries an operation after encountering an error
indication in either of the following ways:
•
Specify the desired value with the RETRIES modifier when issuing the ADD
DEVICE command.
•
Call the SETMODE 15 procedure.
If an error condition persists after the operation has been retried the specified number of
times, an error indication is returned to the application process that requested the
operation.
Note. With the multileaving option, certain variations of this procedure are in effect. See
Multileaving Conversational Mode on page 3-7.