View a spectrum of the noise measurement

You can view the noise spectrum that displays the levels of low frequency (870 Hz - 9 KHz), in-band (9 KHz - 39 KHz), and high frequency noise (39 - KHz - 100 KHz).

Note: Before taking a noise measurement, remove the AC adapter from the Trex unit, if it is connected. This isolates the Trex unit from the local power grid.
Note: The spectrum measurement will fail if the noise amplitude exceeds 1.5 V (peak-to-peak). If you see multiple high-amplitude noise peaks, look for an unattached wire that may cause high noise and saturate the noise detection.
  1. Connect to the FOUNDATION fieldbus device or segment.
  2. On the Fieldbus Diagnostics Overview screen, tap Spectrum.
    A spectrum displays the noise measurements. The highest peaks are outlined in black.

    Example of noise spectrum

  3. If necessary, tap Reset Peak to clear the peak on the spectrum.