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Trigger troubles

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Trigger troubles

Postby Massimo » Thu May 19, 2011 5:43 am

Hi,

I'm writing my own vb.net software for a ps3204A and I have some troubles with triggering.
My aim is to catch 1000 waveforms about 100 uS long on a rise front with a defined threshold in rapid block mode.
During my tests I had used a low frequency sine/square wave generated by the scope itself (from 50 to 500 Hz in separated tests).
I had already tried to work with both setsimpletrigger function and the 3 trigger functions (in the same order as indicated in the programmer manual) but I cannot let the scope works as I need.
In particular the scope catches the signal in a very short time than the expected and the trigger time offset that I read are always 0 or 16-32 nS.
I cannot understand what I'm doing wrong, can someone help me?

Thanks in advance for your reply.
Massimo
Massimo
 

Re: Trigger troubles

Postby Chris » Thu May 19, 2011 3:13 pm

What type of trigger do you need?

Just a simple level trigger (using the ps3000aSetSimpleTrigger)

or a more advanced trigger, such as pulse width?


What conditions do you need to be met in order to trigger?
Chris
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Re: Trigger troubles

Postby Massimo » Thu May 19, 2011 5:51 pm

Hi,

I need quite a simple trigger: rise front (with hysteresis) when the signal pass a certain value.

The other matter is that the time triggertimeoffset(bulk) functions returns all values close to 0. The i-th returned value is the time spent between the oscilloscope runblock firing and the i-th trigger firing, isn't it?

Thanks for your reply.
Massimo
Massimo
 

Re: Trigger troubles

Postby Chris » Fri May 20, 2011 3:31 pm

You say you're using vb.net, so you'll need to use the functions in the ps3000wrap.dll wrapper dll.

Take a look at the ps3000wrap.c to see their parameters.

email support@picotech.com if you have further questions about it.

The triggertimeoffset(bulk) function is used to calculate the time between the 1st triggered sample being taken, and when the signal actually crossed the trigger piont threshold.
Chris
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