Enables in-band retuning and specifies the current frequency, in hertz (Hz), of the RF downconverter.

Syntax

NIRFSA_ATTR_DOWNCONVERTER_CENTER_FREQUENCY

Numeric Value

Data Type

Access

Applies To

1150082

ViReal64

Read/Write

N/A

Remarks


If you set this attribute, any measurements outside the instantaneous bandwidth of the device are invalid. To disable in-band retuning, reset the attribute or call the niRFSA_ResetDevice function.

After you set this attribute, the downconverter is locked to that frequency until the value is changed or the attribute is reset. Locking the downconverter to a fixed value allows frequencies within the instantaneous bandwidth of the downconverter to be measured with minimal overhead, decreasing tuning time.

Valid Values: Any supported tuning frequency of the device

PXIe-5820: The only valid value for this attribute is 0 Hz.

Default Value:

PXIe-5694: The default value for the PXIe-5694 is 193.6 MHz unless you set the NIRFSA_ATTR_SIGNAL_CONDITIONING_ENABLED attribute to NIRFSA_VAL_SIGNAL_CONDITIONING_BYPASSED, in which case the default value is 187.5 MHz.

All other devices: The carrier frequency or spectrum center frequency. NI-RFSA sets this attribute to the default value based on the value of the NIRFSA_ATTR_ACQUISITION_TYPE attribute.

Supported Devices: PXIe-5601/5603/5605/5606 (external digitizer mode), PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5667/5668, PXIe-5694, PXIe-5820/5830/5831/5832/5840/5841/5842