Agilent 34401A capture of one time occurance waveform

[mgparrish]

System overview:

I have a system setup and the main test environment is in C++ but have the capabilty of inputing directly some GPIB commands directly into a "widget".  The widgets are just pre-coded test instructions, like measure frequency, set power supply voltage to something, read ac voltages, DC voltages etc.

The system is all NI stuff, I/O, GBIP host, NI drivers for the main testing application etc.

The system has served well as all the measurements that were needing to be taken are continuous so just need to set up the 34401A VM for the appropriate measurement and then "read".  The captured read from the instruments are placed into an accumulator much like a input into a calculator.

Problem:

In the past since steady state measurements were being taken it is easy to grab those and store into a log file, test against limits, and pass/fail etc.

The problem I am having is that I am not familar enough with grabbing a one occurance measurement and retrieving from the 34401A VM.

The waveform is a ramping up in amplitude and frequency sweeping.
I need to constantly measure the waveform and update the peaks (Min max) each time until the waveform is gone.

I can do this manually thru the instrument front panel by the following:

1. Set AC filter to Slow 3 HZ.
2. Resolution to fast 5 digits
3. Set "Math " to Min - Max.
4. N samples to 50,000
5. Set the range.

Something like that.

I then go in and manually retrieve the Max reading from the front panel.

I just want the VM to store the Max peaks and update each time a new peak occurs.  The problem I am having is the triggering, on the bench the VM will auto trigger and update itself for the new peak, how do I set this up programatically?

If I set fo min-max and 50,000 N samples and use the "read" command the pgm chokes and generates and error, so I obviously doing something wrong thru the GPIB.

I just want the VM to make it's own triggers, store the data in the VM, and then go grab the Max peak from the VM.  Just like I had it do on the bench.

If anyone knows the appropriate GPIB commands please help me if you can!!! thx

[Matt_S.]

Hi mgparrish,

 There are many users of Agilent instruments on this forum, so someone else here may be able to tell you the command you're looking for. On the other hand, if you want a direct answer it might be easier to get this information from Agilent. I would call their technical support and let them know what kind of reading you want to do and ask them what commands in GPIB would work for you.

I hope you find an answer for this, and for the sake of other people with that instrument it would be nice if you post the solution in here when you're done. Then the next time a user has a problem like this they can use your feedback!

Regards,
Matt S.