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 Multipoint Tributary Protocol
Envoy Application Programming Manual—427159-001
5-8
File-System Procedures
File-System Procedures
The application process uses the following Guardian 90 file-system procedures to
interact with Envoy and to communicate with the supervisor station. The file-system
procedures are presented in alphabetic order.
AWAITIO
Waits for completion of an outstanding nowait I/O operation.
CHANGELIST
Changes a designated station’s poll state or select state to active or inactive.
CHANGELIST may be called while the line is being monitored by a call to the
READ procedure.
CLOSE
Terminates access to a data communications line.
CONTROL
Performs the line control operations shown in Table 5-3.
Note that EOT should not be sent to terminate message transmission for error
conditions, because the supervisor may have already polled or selected another
station.
DEFINELIST
Passes the tributary’s address list to Envoy. The format of the address list is
described under Address-List Format on page 5-11. You must call DEFINELIST
after opening the line, but before the first call to READ or WRITE. You may
subsequently redefine the station’s poll and select addresses at any time by again
calling the DEFINELIST procedure.
DEVICEINFO
Returns the device type and configured record length for a line.
Table 5-3. CONTROL Operations for BISYNC Multipoint Tributary
Operation Description
13 Sends EOT (end of transmission)
14 Sends WACK (wait for acknowledgment)
16 Sends TTD (temporary text delay)
20 Monitors the line (without READ); incoming control characters are indicated
by file-system errors.