Envoy ACP/XF Application Programming Manual

Normal Response Mode (NRM) Protocols
EnvoyACP/XF Application Programming Manual–132179
3-43
NRM Nonswitched Point-to-Point
The configured device name of the primary-station line is $PRIM; the configured device
name of the secondary-station line is $SEC. After opening their respective lines, each
application process calls the SETMODE procedure to ensure that the required line
characteristics are properly defined, as follows:
PRIMARY SECONDARY
INT lnr [0:11] := ["$PRIM ", INT lnr [0:11] := ["$SEC",
9 * [" "]], pnum; 10 * [" "]], snum;
. .
. .
CALL OPEN(lnr,pnum,14); CALL OPEN(lnr,snum,14);
CALL SETMODE(pnum,16,%414); CALL SETMODE(snum,16,%410);
Lines opened for exclusive read or write access and for nowait I/O have a default
maximum of 15 concurrent outstanding requests. The SETMODE call sets the stations
for two-way, simultaneous transmission. Both stations are in the disconnect state.
Line monitoring begins when the applications issue a READ request. The primary-
station application issues a CONTROL request to set Normal Response Mode and to
send a SNRM command to the secondary, as follows:
PRIMARY SECONDARY
CALL CONTROL (pnum,13); CALL READ (snum,read^buf,2);
IF <> do error handling; IF <> do error handling;
CALL AWAITIO (pnum); CALL AWAITIO (snum);
IF <> do error handling; IF < > do error handling;
CALL READ (pnum,read^buf,50);
IF <> do error handling;
CALL AWAITIO (pnum);
IF <> do error handling;
The CONTROL, AWAITIO, and READ procedure calls have the following effect on
line activity:
PRIMARY SECONDARY
Read unit enabled. Read unit enabled.
READ call completes with CCE. READ call completes with
CCE.
CONTROL causes EnvoyACP/XF
to send SNRM command.
SNRM,P —————————————>
EnvoyACP/XF automatically
responds to SNRM.
AWAITIO call completes
with CCG and with %20 in
MCW.<3:7> of read buffer.
<——————————————— [UA,F]
AWAITIO call completes
with CCG.
In both stations, a condition code greater (CCG) completion for the AWAITIO call
indicates that the outstanding READ operation was completed by the receipt of a link