ADC Measurements


When M937xA, P937xA, and M9485A work with M9341B Anlog/Digital I/O, you can measure or output DC signal.

Note: When analog inputs are measured along with analog output, the input measurement may have some transient noise if output voltage is changed significantly. The timing and level of transient noise will be varied depending on the load of device for analog output.  Extending dwell time and sampling period can reduce the influence of noise.

 

New Trace (ADC) dialog box help  

On the New Trace dialog, click the Receivers tab.

Activate - check any empty line to create a trace.

Numerator - select from the following:

  • AIx - Input x:  x is Input No.

  • AOCx -  Monitor the current in Amp. of DC output source x:  x is output No.

Denominator - NOT available (ONLY unratioed measurements)

Source Port - The ADC receiver is measured when the specified source port is sweeping. Select None to always measure the ADC receiver.

 

How to Setup Analog Input

 

Using Hardkey/SoftTab/Softkey

Using a mouse

  1. Press Setup > Internal Hardware > PXI Device...

  2. Click M9341 IO Control Setup..

  1. Click Instrument

  2. Select Setup
  3. Select Internal Hardware

  4. Select PXI Device..

  5. Select  M9341 IO Control Setup..

 

Analog In dialog box help

This tab is displayed only when the M9341B is installed.

Note (M9485A):  The M9341B should be placed at next slot of the most right receiver (M9376A/77A). For the M9377A, the M9378A/B can be placed between M9341B and M9377A. Otherwise, the measurement speed becomes slow.  When you make a pulsed measurement (Option 025), it must be placed at next slot of the most right receiver.

Range : Select from 1, 5 or 10 V. Smaller range has better resolution.

Measurement Time : DC measurement time for one point. This can calculated by (Number of Samples) x 20 nsec.   

Number of Samples : Number of ADC samples for one point. One ADC sample takes 20 nsec. Increasing this number improve the stability of DC measurement.

 

 

ADC receiver traces are labeled as shown in the following images:

ADC Traces and other useful VNA functions

Although most VNA functions work with ADC traces, the following may be especially useful.

VNA Functions Not Supported