Advantech PCLS-848-P, User Manual

Page: 43 / 106

CHAPTER 2 INSTALLATION 37
3.4.12. ieppoll
NAME:
ieppoll — Parauel poll.
SYNTAX:
p:=ieppoll;— Microsoft Pascal.
ieppoll(p); — Turbo Pascal.
RETURN VALUE:
p: integer; An integer equals to the result of parallel polling. Value 0-255
of an eight-bit byte represents the parallel poll response of the
devices of the interface bus.
DESCRIPTION:
This procedure conducts a parallel poll of the interface bus. It returns the value
(0-255) of an eight-bit byte representing the response of those devices of the
interface which have been configured to respond to a parallel poll (see the
procedure ieppollc).
BUS ACTIVITY:
ATN and EOI are set true for 25 rnicroseconds.
The parallel poll byte is read.
EOI is set false.
ATN is set false.