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signal from digital input in acquire via console

Posted: Mon Aug 04, 2014 6:03 pm
by adam.polak
Hi!
I have a question - maybe trivial, but I'm struggling with that for a while, so decided to look for help.

I'd like to trigger my acquisition via console by external trigger. I have pulse signal connected to DIO0_P pin and I can clearly see it triggers web page based oscilloscope, but now I'd like to move to the console and I have a problem. My goal is to apply pulse signal to DIO0_P and that the 'acquire' procedure would take one sample every time there will be positive edge in my pulse signal. I tired to set the triggering via 'monitor' while setting value 6 under address 0x40100004, but it seems not working :( ..... I would guess I could modify it in the c code of acquire file but I cannot find the proper place where it is defined. Could anybody help me with that?

At the same time another - similar - question. I'd like to apply another pulse signal (with much lower frequency) to another digital input channel. My idea is to get the positive edge of this signal as the initiation of the 'acquire' function (after acquisition of predefined amount of samples triggered as above, the data would be saved from buffer to the file and acquisition would wait for another positive edge of this DI signal). Could somebody help me and advise how to programme it?

I'm sorry for my very amateur questions, but well - I'm just learning all these things :)
I'll be grateful for any suggestions!

Re: signal from digital input in acquire via console

Posted: Wed Aug 06, 2014 2:40 pm
by Crt Valentincic
I would suggest that you try to modify this simple example.
Your sequence should be as following:
- set trigger source to ext. trigger
- ARM trigger (acquisition will start, write pointer will start incrementing)
- wait for ext. trigger by polling trigger source register (trigger source will be set to 0, and acquisition will stop once trigger condition will be met)
- read the data at trigger pointer location (this is the sample you are interested in)
More information about FPGA acquisition module can be found here.