Envoy Application Programming Manual

Table Of Contents
BISYNC Point-To-Point Protocol
Envoy Application Programming Manual427159-001
3-10
File-System Procedures
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 does not bid for the line. A call to WRITE completes when
the remote station acknowledges the message.
WRITEREAD
Performs conversational mode transmissions and circuit assurance for switched
lines.
Limited conversational mode, in accordance with BISYNC protocol, permits a
receiving station to return text in place of the normal positive acknowledgment of a
message that ends with ETX.
According to the BISYNC protocol, the receiving station is permitted to return text
only once before it must resume the normal ACK0/ACK1 response sequence.
.<13> 0: Secondary station
1: Primary station
.<14:15> 0: Point-to-point, nonswitched
1: Point-to-point, nonswitched
17 1 Specifies intermediate block size in words
18 1 Sets statistics threshold
137 1 Specifies the error code to be returned when a station does
not receive a response to a line bid or to transmitted text
0: Specifies that different error codes are returned for the no-
response conditions
Error 171 (no response on bid/poll) is returned when a
station does not detect a response to a line-bid
Error 162 (operation timed out) is returned when a station
does not detect a response to transmitted text
1: Specifies that error 171 is returned for both no response
on line bid and operation timed out conditions
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.
Table 3-6. SETMODE Operations for BISYNC Point-to-Point (page 2 of 2)
Operation Parameter Description