viGpibCommand

NI-VISA 15.0 Help

Edition Date: June 2015

Part Number: 370131S-01

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Purpose

Write GPIB command bytes on the bus.

C Syntax

ViStatus viGpibCommand (ViSession vi, ViBuf buf, ViUInt32 count, ViPUInt32 retCount)

Visual Basic Syntax

viGpibCommand&(ByVal vi&, ByVal buf$, ByVal count&, retCount&)

Resource Classes

GPIB INTFC

Parameters

Name Direction Description

vi

IN

Unique logical identifier to a session.

buf

IN

Buffer containing valid GPIB commands.

count

IN

Number of bytes to be written.

retCount

OUT

Number of bytes actually transferred.

Return Values

Completion Codes Description

VI_SUCCESS

Operation completed successfully.

Error Codes Description

VI_ERROR_INV_OBJECT

The given session reference is invalid.

VI_ERROR_NSUP_OPER

The given vi does not support this operation.

VI_ERROR_RSRC_LOCKED

Specified operation could not be performed because the resource identified by vi has been locked for this kind of access.

VI_ERROR_TMO

Timeout expired before operation completed.

VI_ERROR_INV_SETUP

Unable to start write operation because setup is invalid (due to attributes being set to an inconsistent state).

VI_ERROR_NCIC

The interface associated with the given vi is not currently the controller in charge.

VI_ERROR_NLISTENERS

No Listeners condition is detected (both NRFD and NDAC are deasserted).

VI_ERROR_IO

An unknown I/O error occurred during transfer.

Description

This operation attempts to write count number of bytes of GPIB commands to the interface bus specified by vi. This operation is valid only on GPIB INTFC (interface) sessions. This operation returns only when the transfer terminates.

If you pass VI_NULL as the retCount parameter to the viGpibCommand() operation, the number of bytes transferred will not be returned. This may be useful if it is important to know only whether the operation succeeded or failed. The command bytes contained in buf should be valid IEEE 488-defined Multiline Interface Messages.

Note Note  The retCount parameter always is valid on both success and error.


Related Topics

INTFC Resource

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