NI RF Signal Generators Help (NI-RFSG 18.1)

Edition Date: June 2018

Part Number: 371025V-01

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C Function Prototype

ViStatus niRFSG_5840_AlignLODaisyChain (ViSession vi, ViBoolean useExternalLo, ViRsrc externalLo, ViConstString resourceNames, ViInt32 portTypesLen, ViInt32[] portTypes, ViReal64 startFrequency, ViReal64 stopFrequency);


Performs an external LO alignment by adjusting the NIRFSG_ATTR_LO_IN_POWER attribute settings for optimal use with the PXIe-5653.

Ensure the PXIe-5840 is unassociated from the PXIe-5653 in Measurement & Automation Explorer before calling this function.

Supported Devices: PXIe-5840


Name Type Description
useExternalLo ViBoolean Specifies whether the PXIe-5653 is used as the external LO.

Defined Values:
VI_TRUE (1) The PXIe-5653 is used as the external LO.
VI_FALSE (0)The PXIe-5653 is not used as the external LO.

Default Value: VI_TRUE

externalLo ViRsrc Specifies the resource name of the PXIe-5653.
resourceNames ViContString Specifies a comma-separated list of resource names that represents the PXIe-5840 devices in the order the LO cables are daisy chained.
portTypesLen ViInt32 Specifies the size of the portTypes array, in elements.
portTypes ViInt32[] Specifies the port type of the daisy-chained PXIe-5840.

Defined Values:

NIRFSG_VAL_PORT_RF_INSpecifies the PXIe-5840 RF IN port. This value is not supported as the first element of an array.
NIRFSG_VAL_PORT_RF_OUTSpecifies the PXIe-5840 RF OUT port.
startFrequency ViReal64 Specifies the lower limit of a span of frequencies, in hertz (Hz).
stopFrequency ViReal64 Specifies the upper limit of a span of frequencies, in hertz (Hz).

Return Value

Name Type Description
status ViStatus Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an instrument driver function to determine if an error occurred.

To obtain a text description of the error code, call the niRFSG_GetError function.

The general meaning of the status code is as follows:

Positive ValuesWarnings
Negative ValuesErrors


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