ADC-42: Sampling - New to Pico

 
Post new topic   Reply to topic    Pico Technology Forum Index -> Parallel Port Products
Author Message
Guest
Guest





PostPosted: Thu Aug 05, 2004 3:22 am    Post subject: ADC-42: Sampling - New to Pico Reply with quote

Hi,

While searching for low-cost compact ADCs for my applications, I found Pico ADC-42 to be an ideal match with my requirement.

Before I proceed with purchase, some questions:
- what is the typical achievable sampling rate? with a Pentium 800MHz processor and Win2000.

- I intend to use this device for realtime data acquisition and some realtime signal processing. Will my application interfere the acquired signal?

Appreciate any advice. Thanks.
Back to top
markspencer
Site Admin
Site Admin


Joined: 07 May 2003
Posts: 610

PostPosted: Thu Aug 05, 2004 10:26 am    Post subject: Reply with quote

Hi,

Thank you for your post.

It is possible to get 15kSamples per second and thus you will ber able to see upto a bandwidth of 7.5kHz in the spectrum. In the scope viewer, to get good definition of a trace you need to take approximately 8 points per cycle. This means that you will be able to see 900 - 1000 Hz traces. However, if you do not casre about definition then higher frequency traces can be viewed as well.

ADC-42 can be used in both Picoscope and Picolog, the latter is the data acquisition software and has two modes 'Real Time Continuous' and 'Fast Block' mode. The first option allows you to collect up to a million samples before the a new file is required. The maximum sample interval in this modeis 1 per millisecond, to achieve this you would have to use the USB to Parallel port adapter.

The second mode will allow the unit to sample at the maximum sample rate, but is limited to a few milliseconds sampling duration.

The ADC-42 when connected to the Parallel port is clocked by the Windows clock for its timing. If another application is running on the PC then this can effect the timing of data sampling. However, this can be resolved by using the USB to Parallel port adapter which will then take over the clocking of the samples.

Best regards,
Back to top
Shanguo
Guest





PostPosted: Tue Aug 10, 2004 5:31 am    Post subject: Samping rate Reply with quote

Thanks for your prompt reply.

We need to do continous sampling with Fs = 5K. We have a National Instrument version which is working like this:
- double buffering; with half buffer of 0.25sec data.
- signal processing functions are performed for each 0.25seconds of data.
- real-time, no stop.

Will the ADC-42 be able to achieve 5kS/s sampling rate in continous mode, and have enough CPU time for signal processing? From your reply, it looks to me that the ADC-42 is only able to do continous sampling at 1kS/s.

Does the package include software drivers/development kits?

Looking forward to your advice.

Thanks and regards,
Shanguo
Back to top
Sarah
Guest





PostPosted: Tue Aug 10, 2004 11:19 am    Post subject: Reply with quote

Hi Shanguo

The ADC-42 will not be able to acheive sample at 5kS/s in Real Time Continuous mode as the software limit for this is 1kS/s. Above 1kS/s, you would have to use block collection and thus there would be gaps between the data blocks.

The package includes unit driver that contains all the routines required for gettings raw data from the ADC-42.

Best Regards
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Pico Technology Forum Index -> Parallel Port Products
All times are GMT
Page 1 of 1

 


Pico Technology topic RSS feed 
Powered by phpBB © 2001, 2005 phpBB Group