Arduino versus LabJack

Using Arduino Installation & Troubleshooting
#1

Hello, i have great problems in measuring an analog value and/or a counter. The frequency has to be 20 Hz!!! That means, i want to receive 20 times per second some analog values.

Attention! The values has to be sampled with exactly 20 Hz! Allways, under all conditions!

With a LabJack it works bad, because there is no triggering possible and i have to stream. So i receive a huge amount of data wich has to be scanned for the right value at the right time and my PC is nearly paralysed. The LabJack can't be triggered external.

My question is: is it possible to trigger (external 20 Hz signal) the arduino? Is it possible to send instructions to the arduino? Is the arduino able to execute the instructions during the 20 Hz stream?

Thanks for reading!

#2

is it possible to trigger (external 20 Hz signal) the arduino? Is it possible to send instructions to the arduino? Is the arduino able to execute the instructions during the 20 Hz stream?

Yes to all the above.

Rob

#3

Only the UE9 supports external triggering, so if you have the U3 or U6 you can only trigger stream scans using the internal clock. You say you want to scan at exactly 20 Hz, however, which sounds like you do want to use the internal clock, so a normal stream should work well for you.

Streaming at 20 Hz is fine, but because it is so slow you likely need a couple extra configuration commands so your software does not timeout waiting for data. You can do that, or just stream faster and toss out the extra data. Streaming at 200 Hz, 2 kHz, or even 20 kHz, puts minimal strain and any reasonably modern computer.

To test, just run LJStreamUD at say 200 Hz and write some data to file.

#4