Digital Discovery - retrigger pattern generator

[Christoph Gollinger]

Dear Forum Members,
we are interested in the pattern generator functionality of the Digital Discovery.
We would like to doublecheck some information before ordering:
 
We want to generate a 4bit (4 output sitnals) pattern of e.g. 30k Samples at 1Meg Samplerate.
The pattern should be triggered by an input of the Digital Discovery unit.
The pattern should be RESTARTED by the trigger input everytime the triggerconidtion is met. E.g. each rising edge of the Input the pattern generation should be restarted.
Even if the trigger event comes during a running pattern.
The pattern is user defined and stored in the Digital Discovery unit. The pattern should be deterministic in timing respective to to the trigger signal.
I attached a drawing of the pattern generation.
Is this functionality possible with the Digital Discovery Unit?
 
Is it true that the pattern buffer size 32k for each output, and the max samplerate is 100 MHz?
 
Thank you for your help
Best regards
Christoph

[attila]

Hi @Christoph Gollinger

All above can be done with DD except that it will only look for trigger when not running, not generating pattern.
The custom device buffer size is 32k (2^15) sample / dio channel.

 

 

[Christoph Gollinger]

Hello Attila,

thanks for your answer.

I am not shure what you meant by "i will only look for trigger when not running, not generating pattern".

Does this mean that outputs of the pattern generator are in defined state (e.g. LOW) until trigger event

occurs and starts pattern generation on the outputs? Or will you look what the behaviour is?

Thank you very much for your help

Best regards

Christoph

 

 

 

 

[attila]

Hi @Christoph Gollinger

The pattern generator looks for trigger only when it is in armed state. The trigger events while running (during wait and run) will be ignored.
You can specify a wait time, delay after trigger before starting the generator.
States: ready -> armed <trigger?> -> <wait> -> run -> <repeat?> -> armed/done

In the WF application the idle (ready, armed, wait, done) output can be specified to be: the initial value, 0, 1, Z (high impedance).
From the WF SDK (python script or custom application) the idle output value can be specified individually for each signal.