Trigger problems

[Scorpi]

Hi,
I´d like to generate a signal and pick it up. I trigger with the AWG trigger, but when I start the program again every time my signal starts at a different position. I need to have it start at the same position always.
But when it runs it is every time at the same position. I try to get the signal at the beginning of it. At the moment I don’t get why every acquisition starts at different time but after the first signal it´s absolute equal at the same position.

[Nils Roos]

I trigger with the AWG trigger

If I understand correctly, you are using the scope's trigger mode 8 or 9.
Could you explain in what order you program the awg and scope ? A link to your source would also help.

[Scorpi]

Yes that is correct I use the mode 8. First I parse the arguments from the console then I initialize the oscilloscope and set the parameters.
These are the parameters that I used:

Code: Select all

t_params[TRIG_SRC_PARAM] = 3; // 3 is AWG trigger mode 8
t_params[TRIG_MODE_PARAM]= 1; // trig_mode:0-auto 1-normal 2-single
t_params[TRIG_EDGE_PARAM]= 0; // 0=pos 1= neg t_params[TIME_RANGE_PARAM] = 1

After this I parsing all the arguments I use.
Then I initialize the oscilloscope and set the parameters.
Now I synthesize the signal and allocate the memory for the oscilloscope right before I write the data to the FPGA and at last I acquire the data an print it to the console.


Thanks for your responses

[Nils Roos]

I assume you modified the function osc_fpga_cnv_trig_source() to parse trig_source: 3 to fpga_trig_source = 8 ...
Do you reset the AWG prior to starting it the first time ?

You know, troubleshooting would be much more effective if I could just look at the complete code instead of having to guess based on vague descriptions.

Cheers
Nils