Dear Roger,

I want to know the method to measure frequency. For example, how can I measure the frequency of sine wave? Could you tell me the concrete wiring configuration?

Thank you

Good morning kangle2miao,

Yes you can. If your signal is less then +/- 2.5 VDC Peak to peak then you can use the analog inputs to read frequency.

Cheers,
Roger

Dear Roger,

I encountered an odd problem when I measured frequency. It followed this, when I measured signal with frequency 400-10KHz, there was no problem.

But when I measured signal with frequency 1-30 Hz, the returned data was wrong, 380Hz or so. Of course, I had changed P12=2000, and the signal was within 5 Vp-p. Could you tell me the reason?

Thank you

Good morning kangle2miao,

It could be due to noise in the signal.
When you have a higher frequency the difference between readings is large and noise won't be an issue. The DT800 is looking for a crossing point, and if the frequency is low, it might be counting crossings due to noise. Try locking the gain to the 1 volt range. This will effectively square up the input signal. You may want to try different gains to find the most effective gain range for your source.

Cheers,
Roger