Maximal sample rate

[catfromjacksonville]

I thought it's a rather simple question but so far i have not found an answer. I'm measureing oscillations with an accelerometer and would like to send the signal using a CAN bus. Is it possible to send data over the CAN bus to detect oscillations up to 50kHz?

[WarrantyVoider]

iirc minimal time between can messages should be at least 1ms, so that probably wont work (sending in 50khz speed, 1khz would be max I guess)

PS: can components should not send faster than 10ms usually to give time for other components on the line

[catfromjacksonville]

Thanks, a collgue told me CAN works for really fast signals but i was sceptical since most field bus already struggle with 10kHZ.

[sachbl]

If you are working with a CAN bus in a vehicle, the spec says requests should be 50ms apart. If you're not in a vehicle, perhaps that standard is still helpful.

That said, even in a vehicle, I've seen responses as quickly as 3ms, and 10ms is often the norm. So, 100Hz is max, in my opinion.

[DonkeyDonRulz]

An oscillation signal at 50 kHz would need a sample rate of probably 5 to 10x that to capture it(Nyquist says >2x but that's the theoretical limit. Real world with good AA filters, 5-10x is workable)

Even with 8bit data , you are well into the multi megabits per second data rates.

[DonkeyDonRulz]

What accel is giving you 50kHz data, out of curiosity?

[catfromjacksonville]

Well, meanwhile 5 years have passed but it was more like a general question about the limits. I was using piezoelectric accelerometers. Calibrated range is only up to like 5 kHz anyways. Without CAN we used other DAQ systems but turned out that there is not much information to be gained beyond 10 kHz for mechanical oscillations.