NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_RATE
- Updated2024-05-08
- 1 minute(s) read
NIRFSA_ATTR_DIGITIZER_SAMPLE_CLOCK_TIMEBASE_RATE
Specific Attribute
| Data type |
Access | High Level Functions |
|---|---|---|
| ViReal64 | R/W | N/A |
Description
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.
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 ≥52.5 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