PXIe-6357 devices can be configured for single-ended and differential analog input measurements.

The following figure shows the analog input circuitry of PXIe-6357 devices.

Figure 2. PXIe-6357 Analog Input Circuitry


The main blocks featured in the PXIe-6357 device analog input circuitry are as follows:

  • I/O Connector—You can connect analog input signals to the PXIe-6357 device through the I/O connector. The proper way to connect analog input signals depends on the analog input ground-reference settings.
  • Mux—Each PXIe-6357 device has one analog-to-digital converter (ADC). The multiplexers (mux) route one AI channel at a time to the ADC through the NI-PGIA.
  • Ground-Reference Settings—The analog input ground-reference settings circuitry selects between differential, referenced single-ended, and non-referenced single-ended input modes. Each AI channel can use a different mode.
  • Instrumentation Amplifier (NI-PGIA)—The NI programmable gain instrumentation amplifier (NI-PGIA) is a measurement and instrument class amplifier that minimizes settling times for all input ranges. The NI-PGIA can amplify or attenuate an AI signal to ensure that you use the maximum resolution of the ADC.

    PXIe-6357 devices use the NI-PGIA to deliver high accuracy even when sampling multiple channels with small input ranges at fast rates. PXIe-6357 devices can sample channels in any order, and you can individually program each channel in a sample with a different input range.

  • ADC—The analog-to-digital converter (ADC) digitizes the AI signal by converting the analog voltage into a digital number.
  • AI FIFO—PXIe-6357 devices can perform both single and multiple A/D conversions of a fixed or infinite number of samples. A large first-in-first-out (FIFO) buffer holds data during AI acquisitions to ensure that no data is lost. PXIe-6357 devices can handle multiple A/D conversion operations with DMA or programmed I/O.