Advantech PCL-848A/B Manual do Utilizador descarregar pdf (Página 34)

28 PCL-848AB User's Manual

3.4.12. PPOLL

Purpose :

This command conducts a parallel poll of the interface bus. It returns the value (0-

255) of an eight-bit byte represent- , ing the response of those devices of the interface

which have been configured to respond to a parallel poll (see the PPOLLC command).

Offset :

PPOLL%=24

Syntax :

CALL PPOLL%(RESPONSE%) ----BASIC

CALL ABSOLUTE(RESPONSE%,PPOLL%) ----BASIC Compiler

Parameter :

RESPONSE% - 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.

Bus Activity :

ATN and EOI are set true for 25 microseconds.

The parallel poll byte is read.

EOI is set false.

ATN is set false.

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Advantech PCL-848A/B Manual do Utilizador Página 34