SNAX/HLS Application Programming Manual

SEND-AND-RECEIVE-DATA Verb
SNAX/HLS Verbs
104707 Tandem Computers Incorporated 5–97
Reply Format
The reply formats are either those described under SEND–DATA, or under RECEIVE–
DATA, depending upon whether the send portion failed or succeeded.
Figure 5–21 shows the SEND–AND–RECEIVE–DATA verb flow. The session is using
definite response and immediate request modes, and the PROFILE in use on the
session indicates USER–RESPONSES is NO. For a full description of this and all other
PROFILE attributes, refer to the SNAX/HLS Configuration and Control Manual.
Figure 5–21. Example of SEND–AND–RECEIVE–DATA
VERB SNAX/HLS SNA FLOW
SEND-AND-RECEIVE-DATA
request
#1:BC,RQE(data)
#2:RQE(data)
#3:CD,EC,RQD(data)
+RSP(#3)
#1:BC,RQE(data)
#2:CD,EC,RQD(data)
+RSP(#2)
RECEIVE-DATA reply
RETURN-CODE=OK
ENTER-SEND-STATE=Y
DATA-TYPE-RECEIVED=
DT-PARTNER-DATA
BOM=1
EOM=2
Note that the response to the partner data is not generated until the data is retrieved
by the application. The IBM SNA Format and Protocol Manual: Architectural Logic
procedure RESPONSES–OWED dictates that if a half–duplex send/receive mode is in
use on an SNA session, a mode of operation dictated by the SNA BIND, then all data
received on the session must be responded to before data can be sent on the session.
Thus all partner data received on such a session by SNAX/HLS must be retrieved by
the application before it attempts to send data. See the SNAX/HLS Configuration and
Control Manual for a description of the implementation of the RESPONSES–OWED
procedure by SNAX/HLS.