Interrupt Subprograms - HP 82479A Owner's Manual

Getting Started
2.10.5 Interrupt Subprograms
The ITIL ITY file in the Data Acquisition Pac contains three general purpose subprograms for use in
new application programs. They incorporate all of the statements required to prepare the HP-71 and the
HP 3421A for a service request interrupt when a digital input channel goes high or low or when all
digital input channels meet a given pattern. The subprograms are:
e¢ MONLOW - Monitor a digital input channel until it goes low (page 3-19).
¢ MONHIGH - Monitor a digital input channel until it goes high (page 3-19).
e¢ MONSLOT - Monitor all digital input channels on a digital I/O card until a specific
condition occurs (page 3-20).
The following example uses the [MIIFHI ZH subprogram to wait until channel 4 on a digital I/O card
(mounted in slot 1) goes high before measuring a frequency on channel S:
18 IMIT3421 Initialize HRF2421
28 FEIMT "Frogram startss "i TIMES® P D Frimt starting time
E CHLL MOMHHIGH14. Ey IH UTILITY F P Call and walt for SEQ
468 IF BE THEM FREIHT ERROR E FED I Test srrorcode
ol FREIMT "SRD received: "i TIMES# F P Frimt time of SEQ
EE FREIMT "Frequency ="iFREDCS) F b Frimt frequency
VEOEHD
The next example uses the MIIM=ZLIT subprogram to wait until channels 0 and 2 are high and all other
channels in slot 2 are low before the frequency is measured:
18 IHIT=421 b Initialize HRFZ421
SE FREINT "Frogram starts: ES D Frimt start time
SE CHLL MOMSLOT 2.5. 255. FE IH UTILITY bait for SEQ
460 IF BE THEM FRIMT PERRORY SE © EHD I Test errorcode
ol FREIMT "SRO received: "i TIMES® P D Frimnt fime of SEE
EE FRINT "Frequency ="3FRERQCS P D Frint frequency
FE ERD
Section 3, "Keywords," contains a detailed description of these subprograms.