SNAX/APC Application Programming Manual

Verb Definitions
SNAX/APC Application Programming Manual—138786
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MC-REQUEST-TO-SEND Verb
MC-REQUEST-TO-SEND Verb
The MC-REQUEST-TO-SEND verb informs the remote TP that the local TP wants to
enter Send state.
When the local TP is in Receive state and has data to send, it issues MC-REQUEST-TO-
SEND to the remote TP. The verb completes immediately because it simply notifies the
remote TP; however, the transition to Send state does not occur until the remote TP
actually enters Receive state (by issuing a RECEIVE-AND-WAIT request or
equivalent).
The local TP detects that the state transition has occurred by issuing an MC-RECEIVE-
AND-WAIT verb request until the WHAT-RECEIVED field contains a SEND or
CONFIRM-SEND (a value of 3 or 5). The remote TP can continue to send data for as
long as necessary before changing to Receive state.
The format for MC-REQUEST-TO-SEND request is as follows:
Request Details
REQ-UOW-CODE
This field must contain the value 1107, which identifies the MC-REQUEST-TO-
SEND verb.
Considerations
•
The local TP must be either in the Receive or Confirm state.
•
MC-REQUEST-TO-SEND results in an expedited SIGNAL request being sent to the
remote LU.
•
If an MC-REQUEST-TO-SEND verb is processing when SNAX/APC receives a
CANCEL system message from the application program, SNAX/APC deactivates
the session and replies to the cancelled IPC. SNAX/APC frees the internal resources
after finishing the processing of the verb.
Request Format
01 MC-REQUEST-TO-SEND-REQ.
02 MC-RS-HEADER.
03 REQ-UOW-ID PIC X(2).
03 REQ-UOW-CODE PIC 9(4) COMP.
Reply Format
01 MC-REQUEST-TO-SEND-REP.
02 MC-RSR-HEADER.
03 REP-UOW-ID PIC X(2).
03 REP-VERB-CODE PIC 9(4) COMP.
03 REP-RETURN-CODE PIC S9(4) COMP.
03 REP-RETURN-CODE-DETAIL PIC S9(4) COMP.