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 Centralized Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
4-9
File-System Procedures
READ
Solicits data from a remote station. A call to READ while the line is in the
CONTROL state (an initial READ) causes Envoy to initiate polling of the tributary
stations specified in the currently defined poll list. When a tributary station responds
to the poll by sending a message, polling halts, Envoy returns the tributary's message
to the application process, and the READ completes. At that point, the line is in the
READ state. Envoy returns an entry number value in the message control word to
the application's line buffer to indicate which station responded. A call to READ
while the line is in the READ state (continuation READ) causes Envoy to
acknowledge the preceding message with the proper ACK0/ACK1 sequence and
accept the current message (if any).
For a normal end-of-transmission (EOT) sequence from a tributary station, the
READ operation completes with a CCL condition code and an error 163 (EOT
received).
A call to READ while the line is in the WRITE state causes Envoy to transmit an
EOT for the WRITE to the tributary. The READ call then acts as an initial READ.
A call to CONTROL 20 after a READ monitors the line for control characters
without sending an acknowledgment for the preceding message (reserved by the
READ). File-system errors are used to indicate what was received from the host.
SETMODE
Alters the line characteristics (Table 4-5).
Table 4-5. SETMODE Operations for BISYNC Multipoint Supervisor
Operation Parameter Description
15 1 Sets timeout duration in 10-millisecond units.
2 Sets number of times to retry.
16 1 Sets line type.
.<1> 0: Specifies normal EOT processing. Returns error 163
when EOT is received.
1: Polls next station when EOT is received.
2 Specifies polling interval in 10-millisecond units.
17 1 Specifies intermediate block size in words.
18 1 Sets statistics threshold.
Note. For a complete list of SETMODE procedures supported by the Envoy protocols, see the
SETMODE procedure description in Ta ble C-5
on page C-27, which also lists the analogous
modifier for these procedures.