PXI-4132 Measurement Timing

The PXI-4132 has unique measurement timing behavior because it is the only NI-DCPower instrument that supports auto zero functionality.

The PXI-4132 measurement circuitry operates in one of the three active states:

  • Signal conversion—The PXI-4132 samples the input signal for the programmed aperture time of the device.
  • Zero conversion—The PXI-4132 samples a zero and uses it to compensate for internal offsets. Zero conversion usually occurs after, and has the same aperture as, the signal conversion.
  • Settling time—The analog circuitry of the PXI-4132 settles before the next measurement state occurs.
    Note Settling time on the PXI-4132 is a fixed period of ≈300 µs. If auto zero is enabled, there will be settling time for the zero measurement as well as the output measurement, resulting in ≈600 µs total settling time.

    • Figure 1 illustrates the sequence of these states for a one sample measurement for which auto zero is on.

    Figure 1. PXI-4132 Measurement Timing

    1378