NI-HSDIO C Function Reference

niHSDIO_ConfigureRefClock

  • Updated2023-02-21
  • 2 minute(s) read

ViStatus = niHSDIO_ConfigureRefClock ( ViSession vi, ViConstString clockSource, ViReal64 clockRate);

Purpose

Configures the Reference clock. Use this function when you are using the On Board Clock as a Sample clock, and you want the Sample clock to be phase-locked to a Reference clock. Phase-locking the Sample clock to a Reference clock prevents the Sample clock from losing alignment with the Reference clock. The driver ignores the Reference clock rate input when the Reference clock source is NIHSDIO_VAL_PXI_CLOCK

Related topics:

Parameters

Input
Name Type Description
vi ViSession Identifies your instrument session. vi was obtained from the niHSDIO_InitAcquisitionSession or niHSDIO_InitGenerationSession function.
Clock Source ViConstString Specifies the PLL Reference clock source.

Defined Values

NIHSDIO_VAL_NONE_STR ("None")—The device does not use a Reference clock.
NIHSDIO_VAL_CLK_IN_STR ("ClkIn")—The device uses the signal present on the front panel CLK IN connector as the Reference clock source.
NIHSDIO_VAL_PXI_CLK10_STR ("PXI_CLK")—Configures the device to phase lock the onboard clock with the clock signal present at the PXI reference clock pin on the PXI backplane. PXI_CLK10 is available for PXI devices, and PXIe_CLK100 is available for PXI Express devices. This clock signal is not supported on PCI devices.
NIHSDIO_VAL_RTSI7_STR ("RTSI7")—The device uses the signal on RTSI 7 as the Reference clock source. This source is only available for PCI devices.
NIHSDIO_VAL_DSTARA_STR ("PXIe_DStarA")—Configures the device to phase lock the onboard clock with the PXIe_DStarA signal present on the PXI Express backplane. This clock signal is supported only on NI 6555/6556 devices.
Clock Rate ViReal64 Specifies the Reference clock rate, expressed in Hz. Refer to NIHSDIO_ATTR_REF_CLOCK_RATE for details.

Return Value

Name Type Description
Status ViStatus

Reports the status of this operation. To obtain a text description of the status code, call the niHSDIO_error_message function. To obtain additional information concerning the error condition, use the niHSDIO_GetError and niHSDIO_ClearError functions.

The general meaning of the status code is as follows:

Value Meaning
0 Success
Positive Values Warnings
Negative Values Errors

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