Measurement Computing GPIB-488.2 - Manual (Page 46)

3-28 IOtech to Associated MCC APIs
986992 GPIB 488.2 Porting Guide
IOtech GPIB Command Associated MCC GPIB 488.2 Command(s)
PPoll PPoll
Syntax
PPoll {
IOtech
} INT WINAPI PPoll(DevHandleT devHandle);
PPoll {
MCC
} PPoll(int board, short *result)
Usage Notes
IOtech’s PPoll (Parallel Poll) command was used to request status information from many
bus devices simultaneously. If a device required service then it responded to a Parallel Poll by
asserting one of the eight IEEE 488 bus data lines (DIO1 through DIO8, with DIO1 being the
least significant). In this manner, up to eight devices could be simultaneously polled by the
controller. More than one device can share any particular DIO line. In this case it was
necessary to perform further Serial Polling (SPoll) to determine which device actually
requires service.
The MCC PPoll (Parallel Poll) command performs a parallel poll. In regard to “Returns,”
result will contain the eight-bit result of the parallel poll. Each bit of the poll result contains
one bit of status information from each device which has been configured for parallel polls. The
value of each bit is dependent on the latest parallel poll configuration sent to the devices
through PPollConfig and the individual status of each device.
The following example is to perform a parallel poll of all devices connected to board 0.
Example:
short result;
PPoll(0, &result);