The two-channel PXIe-5423 supports independent-channel waveform generation.
The following processes outline the generation of analog waveforms with the PXIe-5423:
You can enable or disable digital filtering using niFgen Configure Digital Filter, niFgen_EnableDigitalFilter, or niFgen_DisableDigitalFilter. By default, the digital filter is enabled.
Digital gain multiplies waveform data by a factor you specify with the Digital Gain property or the NIFGEN_ATTR_DIGITAL_GAIN attribute before converting the data to an analog signal in the DAC.
Digital gain can be changed during waveform generation without the glitches caused by switching that are common when changing analog gain. However, the output resolution of the DAC is a function of digital gain, meaning that only analog gain makes full use of the resolution of the DAC.
You can adjust the amount of DC offset added to the signal, up to one-half of the value of the gain setting, by using either the Arbitrary Waveform Offset property or DC Offset property, or the NIFGEN_ATTR_ARB_OFFSET or NIFGEN_ATTR_FUNC_DC_OFFSET attributes.
You can adjust the amount of attenuation by configuring the Arbitrary Waveform Gain property or Amplitude property, or the NIFGEN_ATTR_ARB_GAIN or NIFGEN_ATTR_FUNC_AMPLITUDE attributes. NI-FGEN calculates and sets the correct amount of attenuation required, corresponding to the gain setting.
By default, NI-FGEN automatically selects the amplifier path the signal passes through based on the gain or amplitude setting.
|Maximum Gain (Vpk-center)||Maximum Amplitude (Vpk-pk)|
|50 Ω load impedance||6||12|
|1 MΩ load impedance||12||24|
Alternatively, you can use the Analog Path property or the NIFGEN_ATTR_ANALOG_PATH attribute to set the signal path to remain constant regardless of the gain setting for applications requiring only one of the amplifier paths. Configuring a constant signal path through the low-gain amplifier path regardless of the gain setting affects the maximum output value allowable for that particular gain setting: The maximum gain setting for signals configured to use the low-gain amplifier path is 2.75.
You can adjust the amount of attenuation by configuring either the Arbitrary Waveform Gain property or Amplitude property, or the NIFGEN_ATTR_ARB_GAIN attribute or NIFGEN_ATTR_FUNC_AMPLITUDE attribute. NI-FGEN calculates and sets the correct amount of attenuation required, corresponding to the gain or amplitude settings.
At this point, the signal has an applied maximum attenuation of 51 dB. After this point, the signal will continue to digitally attenuate.
You can enable or disable analog output using niFgen Output Enable or niFgen_ConfigureOutputEnabled.