Measuring grid frequency


I’m gonna reference this post Measuring the main power grid frequency

I’m trying to measure the frequency (60hz) but I’m puzzled by the wiring. I have a 120 to 24vac transformer going straight into pins 1 and 2. Also getting -1 #qnan on the xval value in the project.

Card I’m using is a airate-hfi

Here is how I have the SNAP module configured:

And a snapshot of my groov View screen showing it in action just now:

I just have it wired with a 24v AC step down transformer.
I also have the low pass filter with the capacitor and resistor that I talk about in the blog, but do note that the filter will not stop it from working, it just removes the spikes, so the qnan error has nothing to do with the filter.

For this module to give a #qnan error, the frequency has to be out of range.
How have you got the module scaled?

One of the guys from opto helped me out. We found that I was running different firmware versions. Updated everything from 8.0 to 10.4

what have u found to be better. 1s refresh rate or .1?

There is no hard and fast correct answer to that.
It will depend on your application.

Sounds like you got things working after the firmware update?
Did you build a low pass filter for the input?