Measurement-computing GPIB-488 Instrukcja Użytkownika Pobierz pdf (Strona 28)

Chapter 3 GPIB 488.1 Library Reference

GPIB-488 3-15 Programming Reference Manual

IBDEV

Obtains a device handle for a device whose name is unknown. It opens and initializes the

device with the configuration given.

Syntax

C device = ibdev (int boardindex, int pad, int sad,

int timeout, int eot, int eos)

Parameters

boardindex identifies the GPIB Interface Board with which the device descriptor is

associated. It is an index in the range 0 to (total number of boards - 1).

pad is the primary address of the device. Available addresses range from 0 to 30.

sad is the secondary address of the device. There are 31 secondary addresses available. value

can be 0, or from 96 to 126 decimal; see Appendix A, Multiline Interface Messages. If 0 is

selected, the driver will not expect the device to require a secondary address.

timeout is the timeout of the device. This is a value from 0 to 17 which corresponds to

timeout value ranging from 10 usec to 1000 sec. See Table 3-6, Timeout Codes, for a list of

timeouts and corresponding values.

eot when writing to a device, eot specifies whether or not to assert EOI with the last data byte.

If eot is non-zero, EOI is asserted. If eot is 0, EOI is not asserted.

eos specifies the End-Of-String termination mode to be used when communicating with the

device. See Table 3-4, Selecting EOS, for a description of special formatting features of this

argument.

Returns

device will contain the assigned descriptor or a negative number. If device is a negative

number, then an error occurred. Two types of errors can occur:

•An

EDVR or ENEB error is returned if a device is not available or the board index specifies

a non-existent board.

•An

EARG error is returned if illegal values are given for pad, sad, timeout, eot, eos.

iberr will contain an error code, if an error occurred.

Usage Notes

This routine returns the device handle of the first available user-configurable device it finds

in the device list.

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