National Instruments GPIB-PC - Manual (Page 139)

BASICA/QuickBASIC GPIB-PC Function Calls Section Four A
GPIB-PC User Manual 4A-64 ©National Instruments Corp.
BASICA/QuickBASIC BASICA/QuickBASIC
IBRPP IBRPP
Purpose: Conduct a Parallel Poll
Format: CALL IBRPP (BD%,PPR%)
Remarks: BD% specifies a device or an interface board. PPR%
identifies the variable where the parallel poll response byte
is stored.
Device IBRPP Function:
When BD% specifies a device, all devices on its GPIB are polled in
parallel using the access board of that GPIB. This is done by executing
the board
IBRPP function with the appropriate access board specified.
Board IBRPP Function:
When BD% specifies a board, the IBRPP function causes the identified
board to conduct a parallel poll of previously configured devices by
sending the IDY message (ATN and EOI both asserted) and reading the
response from the GPIB data lines.
An ECIC error results if the GPIB-PC is not CIC. If the GPIB-PC is
Standby Controller, it takes control and asserts ATN (becomes Active)
prior to polling. It remains Active Controller afterward.
In the examples that follow, some of the GPIB commands and addresses
are coded as printable ASCII characters. When the values to be sent
over the GPIB correspond to printable ASCII characters, this is the
simplest means of specifying the values. Refer to Appendix A for
conversions of numeric values to ASCII characters.