Specifies the frequency, in hertz (Hz), of the external clock used as the timebase source if you set the NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_SOURCE attribute to an external source, such as NIRFSA_VAL_CLK_IN_STR, NIRFSA_VAL_LO_REF_CLK_STR, or NIRFSA_VAL_DOWNCONVERTER_LO2_OUT_STR

Syntax

NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_RATE

Numeric Value

Data Type

Access

Applies To

1150022

ViReal64

Read/Write

N/A

Remarks


**PXI-5661**If this attribute is set to a value less than 60 MHz, signals at frequencies just above the 20 MHz passband of the downconverter may be aliased back into the passband. This aliasing occurs because the IF frequency of the downconverter is 15 MHz, and the upper end of the passband is 25 MHz. At sampling rates below 60 MHz, the Nyquist frequency is close to the end of the passband and creates aliases that are not filtered effectively by the downconverter.

Units: hertz (Hz)

Valid and Default Values:

Device

Valid Values

Default Value

PXI-5661

Any frequency 226552.5 MHz

100 MHz

PXIe-5663/5663E/5665/5667

150 MHz

150 MHz

PXIe-5668

2 GHz

2 GHz

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668