usb-9215A

[Bob08]

usb-9215A with VB.Net. Is it possible to take a reading and send it to the 9215 memory instead of getting the response with the function  'ReadSingleSample()' or to use in analog input as trigger. I would like to take synchronized readings at 200 per second for 10 sec, to store them in the 9215 memory and than be able to read the results from the 9215 memory. 'ReadSingleSample' is too slow and 'ReadWaveform" gives me asynchronized readings.

[Austin_S]

Bob,

The ReadSingleSample function is reading data from the buffer in RAM, which should be able to read data at the sample rate you specify.  A couple of questions to try to clarify a few things:

What do you mean it is "too slow"? 

Also, what are you trying to synchronize this reading with?  Is it another signal from the same device or another source?

What is your 'number of samples' set to?  Does this match the settings from the other reading that you're trying to synch with?

[Bob08]

Hi Austin,

My application is a surface scan of a photodiode. It consist of two motors (X & Y axis) moving a beam and the Usb-9215 to read the signal output from the photodiode. The algorithm consist of moving the motor to a different position and than taking a voltage measurement for around 10000 readings per scan. Reading the voltage is time consuming. Moving the motors takes 10 sec per scan but when I read each voltages using 'ReadSingleSample' add 60 sec per scan. So what I would like to do is when the motor get to the new position, I can send a pulse that could be use as a trig for the  9215 (can use an analog input), the 9215 reads the voltage and send it to the a memory and only when the scan is finished, I would like to read the results. Maybe I will have to buy a digital module because the  9215 can't be use for triggering.

Thanks,

Richard Hamelin

Excelitas technologies

[Austin_S]

Richard,

Thanks for clearing that up.  What happens when you increase your sample rate?

If it's still running slowly after doing that, then we'll look at how we can do this with your hardware.

[Bob08]

Austin,

Now It works fine. I did a thread to move the motors and I used function 'beginreadmultisample' & 'endreadmultisample' in another thread to read the voltages.

Thanks,

Richard