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
Burroughs Point-To-Point Protocol
Envoy Application Programming Manual—427159-001
9-4
File-System Procedures
CLOSE
Terminates access to a data communications line.
DEVICEINFO
Returns the device type and configured record length for a line.
FILEINFO
Returns error information and characteristics about an open file.
HALTPOLL
Forces immediate termination of the current outstanding READ operation. If text is
being received when HALTPOLL is called, the READ is allowed to complete
normally, as though HALTPOLL had not been called; if text is not being received,
the READ completes with error 162 (operation timed out).
OPEN
Establishes communications with a line. A line can be opened by only one process
(and its backup) at a time.
READ
Monitors the line and accepts any incoming messages.
A call to READ while the line is in the CONTROL state (an initial READ) causes
Envoy to acknowledge a line bid by the remote station and accept the first message
from the remote.
A call to READ while the line is in the READ state (a continuation READ) causes
Envoy to acknowledge the preceding message with the proper ACK0/ACK1
sequence and accept the current message.
The normal end of transmission by the remote station is indicated by a CCL
condition code returned from a call to READ and by an error 163 (EOT received). A
call to READ while the line is in the WRITE state causes Envoy to transmit an EOT.
The READ then acts as an initial READ.
Table 9-2. CONTROL Operations for Burroughs Point-to-Point
Operation Description
13 Sends EOT (end of transmission). Used to clear the network after an error
occurs.
15 Enables RVI (reverse interrupt)
17 Enables connection by setting the data terminal ready (DTR) signal.
18 Disables connection by clearing DTR.