OSI/TS Configuration and Management Manual

OSI/TS Configuration and Management Manual—424831-001
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Message Control Word Summary
When you use the file-system calls WRITE, READ, and WRITEREAD to control a
transport connection, the first two octets of the buffers contain the MCW (message
control word).
The MCW contains information passed in both directions between your application and
the OSI/TS subsystem. Your application uses the MCW to issue specific transport
service requests to OSI/TS and to configure the OSI/TS subsystem to be a connection-
establishment responder. OSI/TS uses the MCW to indicate incoming connection
requests, expedited transport-data packets, and data overflows.
Table A-1
summarizes how your application uses the MCW in WRITE and
WRITEREAD calls.
Table A-2 shows the interpretation of the MCW returned from OSI/TS on certain READ
and WRITEREAD call completions.
Table A-1. Write Buffer Message Control Word Summary
MCW Bit Number* Value Meaning
00
1
Request other than connection-establishment request.
Connection-establishment request.
10
1
Prepare for incoming CR-TPDUs.
Initiate a connection.
20
1
OSI/TS handles response protocol.
Application handles response protocol.
30
1
Do not accept connection.
Accept connection.
40
1
Not defined.
Release connection.
80
1
Normal data request.
Expedited data request.
14 0
1
Not defined.
Request status information.
15 0
1
Data is complete.
More data needs to be sent than you allowed space
for in the write buffer; issue WRITE or
WRITEREAD call to send more data.
* Bits not listed are not defined.