Entering SEND state

Application programs that successfully allocate a conversation are automatically designated the sender and enter SEND state. Assuming normal completion of the RCVFMH5, the conversation partner becomes the receiver and enters RECEIVE state. The receiving side can either request to send information, or wait until the partner relinquishes the role.

In general, the conversation is in SEND state after the successful completion of:

An APPCCMD CONTROL=ALLOC macroinstruction
An APPCCMD CONTROL=SENDFM5 macroinstruction
An APPCCMD CONTROL=RECEIVE macroinstruction, and the confirm indicator in the what-received field is off and the send indicator in the what-received field is on
An APPCCMD CONTROL=SEND, QUALIFY=CONFRMD macroinstruction after an APPCCMD CONTROL=RECEIVE macroinstruction in which both the confirm and send indicators in the what-received field were set on
An APPCCMD CONTROL=SEND, QUALIFY=ERROR macroinstruction
One of the APPCCMD CONTROL=SEND macroinstructions used to send information

The receiving side can request permission to send by issuing the APPCCMD CONTROL=SEND, QUALIFY=RQSEND macroinstruction. If the conversation partner accepts the request, it surrenders its right to send by preparing to receive information or receiving information. (In the case of VTAM® application programs, this would mean issuing either the APPCCMD CONTROL=PREPRCV macroinstruction or the APPCCMD CONTROL=RECEIVE, QUALIFY=SPEC macroinstruction.)