Measurement Computing DT8824 DAQ Sampling Time Issue

[Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>]

Hi

 

We are using the DT8824 DAQ with our own asyn-driver and the system is working fine with few seconds sampling rate. Recently there have been requirements to use faster sampling rates up to 0.2 seconds. Upon investigation, I could not go below 0.8 seconds, going below that will always give an empty scan record returned by the DAQ itself regardless of the ADC frequency and the number of samples requested. The aforementioned sampling rate is implemented as a sleep in the main thread, on each iteration we do this sequence of commands:

 

:AD:ABORT

:AD:ARM

:AD:INIT

Sleep

:AD:FETCH?

 

As I said this has been working fine for 1 second and maybe few more seconds sampling rates. Here is the driver we wrote https://github.com/SESAME-Synchrotron/xafs-dt8824-daq/ . Notice that the same scenario happens in a python script we wrote that uses the same interface as the driver itself. Any feedback is highly appreciated.

 

Best Regards,

Abdalla Al-Dalleh

Control Engineer

SESAME

P.O. Box 7, Allan 19252, Jordan
Tel: +96253511348

Fax: +96253511423

Email : abdalla.ahmad at sesame.org.jo
Website: www.sesame.org.jo