Pico Technical Support and Discussion Forum

alciom · Guest

Hi,
For an ultrasonic measurement application I need to sample a signal at 100Msps during some tens of microseconds (say 2000 points), but to repeat this measurement every 100ms at least and to transfer them in real time to a specific software running on the PC. One channel only with external trigger.

Is a product like your ADC212/100 compatible with this requirement ? What is the best roundtrip delay when doing repetitive 2000-points acquisition through the supplied DLL ?

Many thanks,
Yours,
Robert

markspencer · Site Admin Joined: 07 May 2003 Posts: 610

Hi,

Thank you for your enquiry.

The ADC-212/100, unfortunately, is not capable of downloading 2000 points and being set up again for another run within the 100ms that you require. To download the data it would take 600ms plus time to set up the unit again. This is based on a 100kHz download across the parallel port. Unfortunately, the USB adapter will not increase the download speed either.

Best regards,
Mark S.

alciom · Guest

Thanks Mark for this answer, however I'm quite surprised that it is negative : I've read on another post in this forum that the "arming" duration is abound 55ms (and seems to be quicker with the adc200_set_rapid function, as the documention indicate a refresh rate of 200 cycles/s best case), and downloading 2000 points x 12 bits at 100KHz on a 8 bit path should take 40ms, no ?

Robert

markspencer · Site Admin Joined: 07 May 2003 Posts: 610

Hi,

Thank you for the interest, unfortunately, the data samples are downloaded as 4 bit nibbles so therefore, it is 2000 x 3 downloads at 100kHz, equates to 60ms, (a mistake in my first calculations), plus the time to reset the unit. Although, you can use the set_rapid function to decrease the set up time, it only reduces it if the next set up is exactly the same as the previous set up.

It could be very close to your 100ms, one way or the other.

Best regards,

Pico Technology

Pico Technical Support and Discussion Forum