count edges with 6036e

[yaelle]

Hello !

I am currently trying to count photons with a PCMIA 6036e. 

I have to detect a TTL signal ; each photon correspond to a pulse. So I tried to count rising edges, since one rising edge = one photon. I want to use either digital line or counter. Moreover, I have to count the rising edges for a limited time (typically 1s).

I have tried several VIs, but none of them work. I either don't have an error message, but only 0 as a result, or an error message saying data were overwritten before they could be read.

The problem does not come from the card, since it can count the rising edges in MAX. I have also tried examples such as "count digital events", but they give me the same error.

I would appreciate any help !

thanks,

Camille

[Mathieu_R.]

Hello,

Check carefully the wiring of your signal to the DAQ board; there is to main input for counter application, the source and the gate. Depending on the measurement you do, you have to wire your signal to the gate or to the source. In your case, the acquisition type should be a simple event counting. Using CTR0, the input signal should be wired to PFI8 (PFI3 for CTR1).

The specification of the PCMCIA-6036E mention that the minimal pulse duration you can handle is 10ns in edge detect mode. If the pulse you measure  are shorter, you will not be able to see it.

Regards,