(2 ) T h e c o n tr o l le r t r i g g e r s m e a s u r e m e n t u n d e r a S Q m o d e a s n e e d s
c o m e u p . T h e c o n tr o l l e r c a n e x e c u te o t h e r p r o g r a m s u n t i l th e
m e a s u r e m e n t e n d s . A f t e r f i n i s h i n g t h e m e a s u r e m e n t , t h e
c o n t r o l l e r a c c e p t s a s e r v i c e r e q u e s t f r o m t h e e q u i p m e n t , r e a d
d a t a , a n d t h e n g o b a c k t h e p r e v i o u s e x e c u tio n a g a i n .
T h is e x a m p le a s s u m e s t h a t o n ly a n e q u ip m e n t s e n d s a s e r v i c e
r e q u e s t .
CD E x a m p l e f o r P C 9 8 0 1 s e r i e s
( u s i n g N 8 8 B A S I C t h a t is n o t f o r M S -D O S )
• P r o g r a m
(1/2)
1000
1010
DFF SEG=&H60
1020
AX=PEEK(4H9F3)
1030
A M AND &HBF
1040
POKE &H9F3, A%
1050
ISET IFC
1060 ISET REN
1070
CMD DEL IM=0
1080
CNT=8
1090
ON SRQ G0SUB *SRQR0UTINE
1100
PRINT eCNT;"C"
1110
PRINT @CNT;’F1, G2, SO'
1120
1130
' ********** MAIN ROUTINE **********
1140
SRQ ON
1150
FOR 1 = 1 TO 1000 : NEXT I
1160
PRINT 8CNT:'E"
1170 FLAG=0
1180
IF FLAG=1 THEN 1160
1190
GOTO 1180
1200
END
4-22