
Conducting a Parallel
The PPOLL (Parallel Poll) function returns a single byte containing up to
Poll
8 status bit messages for all devices on the bus capable of responding to
the poll. Each bit returned by the function corresponds to the status bit of
the device(s) configured to respond to the parallel poll (one or more
devices can respond on a single line). The PPOLL function can only be
executed by the controller. It is initiated by the simultaneous assertion of
ATN and EOI.
Example:
Response
Disabling Parallel Poll
The PPU (Parallel Poll Unconfigure) statement gives the controller the
Responses
capability of disabling the parallel poll responses of one or more devices
on the bus.
Examples:
The following statement disables device 5 only:
PPOLL UNCONFIGURE
705
This statement disables all devices on interface select code 8 from
responding to a parallel poll:
PPOLL UNCONFIGURE 8
If no primary address is specified,
bus devices are disabled from
responding to a
poll. If a primary address is specified, only the
specified devices (which have the
poll configure capability) are
disabled.
HP
Programming Reference
Status Reporting
B-11