Agilent 34401A TriggerMultiPoint Number of Trigger

[tatuo]

Thank you for looking this question.

I could get multi trigger data from labview which I mentioned previously. Thank you very much for Dennis's advice.

http://forums.ni.com/t5/LabVIEW/Agilent-34401A-TriggerMultiPoint/m-p/1424858

However, multimeter cannot measure more than 256 points... according to data-sheet it can measure up to 512 at 1 time, and SCPI can measure 512.

Also, my program behave differently from SCPI command which is

CONF:VOLT:DC 10,0.0001

ZERO:AUTO ONCE

TRIGger:SOURce EXTernal

TRIGger:COUNt 500

INITiate

FETCh?

Also, first 10 data (agilent fetch outputs 1 array has 10 rows at each cycle) is missing... I think my array design is bad...

Could you please give me an advice?

Many thanks for using your time.

[Liam_A]

Hi Tatuo,

Regarding the VI that you attached, you may need to put some sort of timing in the while loops. The build array function with the initializing constant can also be changed to reduce chances of problems by using the initialize array vi and then using shift registers across the while loop to store data between iterations.

As for the memory only storing 256 points, have you tried running any of the basic examples in LabVIEW Find Examples folder by searhcing 34401? These examples contain the correct architecture and some default settings from which to build on. 

It may be an idea to run these and see if you still get the same problems, with the trigger count and sample count set to the required values.

Please let me know how you get on as there may be other avenues wwe can explore!

[tatuo]

Thank you for your advice.

I have tried a sample program (Agilent 34401 Read Multiple Measurements.vi) from NI. Also, the program that I attached was modified from the sample program. 

The sample program can measure only 50 samples (Sample Count -default 10), the multimeter alerts error after 50 samples.

I just want to run SCPI command mentioned above...

50 samples at read, 256 samples at fetch, Is it a specification of labview?

Does NI have manual for the Agilent 34401 instrument driver? If you have could you please post on here or tell me where I can get?

[Liam_A]

Hi there Tatuo,

I am afraid that we don't seem to have an accessible manual for the Agilent 34401 drivers, however there is some useful material in the functions palette. Useful information can be found in the block diagram for "VI Tree" in the Agilent drivers function palette with regards to building the application.

With regards to the example code that you used, by increasing the Timeout value you can take more values - I have trialled this on my computer and it seems to allow me to take multiple values. The VI you attached seems to cause the DMM to freeze in my case, however I will continue to look into this in the meantime.

Best regards,

[jjp377]

Instrument user/programming manual is available on Agilent's website.

[Liam_A]

Hi there again Tatuo,

I am unable to find anything that specifies that the fetch command can only take 256 readings, however, there may be a time limit associated with it.

I have found this material that I think may be able to help you

http://zone.ni.com/devzone/cda/tut/p/id/2927#toc2

It may be an idea to query the instrument for the number of readings in memory just to check.

[tatuo]

Dear Liam,

Labview is very deep... I have just begun to use the labview since last week.

Thank you very much for your advice and kind help!

I found similar program in example program from NI, "Agilent 34401 Acquire and Chart - External Triggered", but it fetches data every 10 samples, doesn't wait until 512 samples...

The other NI sample program, "Agilent 34401 Acquire and Graph - SW Triggered" works very similar to what I want. I will make the program based on this.

I will post the new .vi code when I run the multimeter successfully.

Many thanks for using your time.

Tatsuo