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Ibfind (bdname,bd), Ibcmd (bd,buf,cnt) and ibcmda (bd,buf,cnt), Ibrd (bd,buf,cnt) and ibrda (bd,buf,cnt) – National Instruments GPIB-PC User Manual

Page 53

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GPIB-PC Functions — Introduction

Section Three

GPIB-PC User Manual

3-10

©National Instruments Corp.

IBFIND (bdname,bd)

This is the same as the Group I function except that boards are assigned
names at configuration time in the form

GPIBn

, where

n

is a board's

decimal number (0, 1, 2, ...) within the computer. For instance, in a
system with two GPIB boards, the first is named

GPIB0

and the second

GPIB1

.

IBCMD (bd,buf,cnt)

and

IBCMDA (bd,buf,cnt)

Both functions use the specified board to write commands from memory
to the GPIB. The messages are sent synchronously using

IBCMD

and

asynchronously using

IBCMDA

. These command functions are used, for

example, to address and unaddress GPIB devices and to send interface
messages that enable and disable devices for serial and parallel polls,
that clear and trigger devices, and that lock out front panel control of
devices.

IBRD (bd,buf,cnt)

and

IBRDA (bd,buf,cnt)

Both functions use the specified board to read from a device that has
already been addressed to talk (for example, by the

IBCMD

or

IBCMDA

function). The syntax for these low-level functions is the same as their
high-level counterparts of Group I and III. The software automatically
differentiates bd descriptors that refer to devices from those that refer to
boards, and executes the read operations appropriately.

IBRDI

and

IBRDIA

are also available in BASIC for binary transfers to

an integer array.