Envoy Application Programming Manual

Burroughs Point-To-Point Protocol
Envoy Application Programming Manual—427159-001
9-5
Message Formats
SETMODE
Alters the line characteristics (Table 9-3).
WRITE
Transmits data to the remote station. The first call to WRITE while the line is in the
CONTROL state (an initial WRITE) causes Envoy to bid for the line on behalf of
the application process. The message associated with the initial WRITE is
transmitted when the remote station acknowledges the line bid. Subsequent calls to
WRITE while the line is in the WRITE state (continuation WRITEs) send
subsequent messages, but do not bid for the line. A call to WRITE completes when
the remote station acknowledges the message.
Message Formats
A message is defined as the information transmitted over a communications line as a
result of a single call to the READ or WRITE procedure.
The information put into the buffer of an application process by a READ or taken from
the buffer by a WRITE consists of two parts: a message control word (MCW) and a
message.
The MCW is ignored in Burroughs point-to-point protocol, but must be included as the
first word in the buffer and is counted as 2 bytes in the count.
Table 9-3. SETMODE Operations for Burroughs Point-to-Point
Operation Parameter Description
15 1 Sets timeout duration in 10-millisecond units.
2 Sets number of times to retry.
16 1 Sets line type.
.<11> 0: Disables ID exchange.
1: Enables ID exchange.
.<13> 0: Specifies secondary.
1: Specifies primary.
.<14:15> 0: Specifies point-to-point, nonswitched.
1: Specifies point-to-point, switched.
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.