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
ADM-2 Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
7-31
WRITEREAD Procedure (Transmit a Send Function)
Table 7-10 lists the file-system errors that can occur on a WRITE.
WRITEREAD Procedure (Transmit a Send Function)
The WRITEREAD procedure is used to transmit a send function to a terminal and read
back the requested data. If the line is in the READ state when a call to WRITEREAD is
made (that is, there is an outstanding [unacknowledged] message in the network), Envoy
acknowledges the message with an ACK sequence then reads the EOT sequence from
the terminal.
WRITEREAD Procedure (Line in CONTROL State)
A WRITEREAD while the line is in the CONTROL state (Example 7-15) is used to
transmit a send function to a terminal. The send function directs the terminal to return
some specified subset of its screen. The data from the terminal is returned to the buffer
specified to WRITEREAD.
Table 7-10. WRITE File-System Errors
Error Numbers Description Resultant Line State
0 No error. A terminal was selected and the
message in the buffer of the application pro-
cess is written to it.
READ
160 Request is invalid for device state; protocol
error.
unknown
161 Impossible event occurred for line state. unknown
162 Timeout on selection. The selection was
attempted the number of times specified by
the retry value.
CONTROL
163 EOT received. An EOT was received while
waiting for an acknowledgment.
CONTROL
167 EOT in response to selection. The terminal
rejected the selection.
CONTROL
168 NAK in response to selection. CONTROL
172 Reply not proper for protocol. The data
received while waiting for a response to the
poll sequence was not proper for the ASCII
protocol.
CONTROL
173 Transmission error. The message received
was in error and a NAK sequence was sent
the number of times specified by the retry
value.
CONTROL
177 Text overrun. The length of the message
received exceeds the length specified in the
read count parameter. The READ was
attempted the number of times specified by
the retry value.
CONTROL