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General => Technical support => Topic started by: acxysty on September 10, 2015, 09:07:58 AM

Title: Lowest frequency measured by Nano
Post by: acxysty on September 10, 2015, 09:07:58 AM
Dear All

We need to monitor a sensor generating a low frequency signal ( 5 to 50 Hz).
Is it within the range of PULSEFREQUENCY function or is it too low ?

Regards

Thierry
Title: Re:Lowest frequency measured by Nano
Post by: support on September 10, 2015, 09:45:27 AM
Yes you can measure from 5Hz to 50Hz using the PULSEFREQUENCY function but the resolution is 1Hz.

You can achieve fractional frequency very accurately in this low frequency range if you use PULSEPERIOD function, which returns the period in 1us or 0.1us (configurable - see User's Manual).


The frequency will be the inverse of the period. So you can get down to 0.01Hz by:

F_requency = 100000000/PULSEPERIOD(1)

if PULSEPERIOD is configured to returns 1us.

So if F = 1234 means 12.34 Hz.