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
Asynchronous Line Supervisor Protocol
Envoy Application Programming Manual—427159-001
10-7
Retries
Retries
Line operations are subject to transmission errors such as of line errors, nonresponding
terminals, and incorrect modem-line states. When these types of errors occur, Envoy
passes an error indication to the application process. The application must then
determine what action to take for recovery and retries.
Timeouts
The Envoy Asynchronous Line Supervisor uses both line-timeouts and file-system
timeouts.
You can designate a line timeout value in either of the following ways:
•
Specify the desired value for the TIMEOUT modifier when issuing the ADD
DEVICE command.
•
Call the SETMODE 15 procedure.
SETMODE 15 parm1 = timeout in 10-millisecond units.
The default timeout values for the asynchronous line supervisor (PENVASC profile) and
read-only port (PENVSIM profile) are given in Table 10-2
.
The exact meaning of the line timeout value varies according to the procedure being
executed (Table 10-3
).
Note. Envoy does not retry operations for the asynchronous line supervisor protocol. The
RETRIES modifier has no effect on lines configured for this protocol.
Table 10-2. Default Timeouts
Profile Default Timeout Value
PENVASC 2.7 seconds
PENVSIM 1.5 seconds
Table 10-3. Effect of Timeouts
Procedure Effect of Timeout Value
WRITEREAD Determines the period of time Envoy waits for an acknowledgment after
sending a message to the terminal.
READ Determines the period of time Envoy waits for a message from the
terminal.
SETMODE 15 Specifies the period of time that a break signal is output.