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
3-9
File-System Procedures
OPEN
Establishes communications with a line. A line can be open by only one process
(and its backup) at a time.
READ
Monitors the line and accepts any incoming messages. The first call to READ
following the call to OPEN for the line sets the data terminal ready (DTR) signal.
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 to 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 or ACK1
sequence and to accept the current message.
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.
The normal end of transmission by the remote station is indicated by a CCL
condition code returned from a call to READ and 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.
SETMODE
Alters various line characteristics, as shown in Table 3-6.
Table 3-6. SETMODE Operations for BISYNC Point-to-Point (page 1 of 2)
Operation Parameter Description
15 1 Sets timeout duration in 10 millisecond units (do not use for
SWIFT)
2 Sets number of times to retry (do not use for SWIFT)
16 1 Sets line type
.<3> 0: Specifies normal BISYNC CRC calculation
1: Specifies SWIFT BISYNC CRC calculation
.<10> 0: Disables BISYNC multileaving mode
1: Enables BISYNC multileaving mode
.<11> 0: Disables ID exchange
1: Enables ID exchange
.<12> 0: Specifies half-duplex line
1: Specifies full-duplex line