An image showing PicoScope 7 Automotive's Frequency counting feature

Frequency counting

What it does

Frequency counting (available with PicoScope Automotive 4000 series oscilloscopes) calculates and displays the frequency (in units of cycles per second, Hz) of one of your waveforms as it changes in real-time.

Note: Frequency counting can be applied to waveforms on only one channel at a time.

How it can help you

Sometimes the component you are testing does not send or receive waveforms with changing amplitudes and, instead, the important waveform information is conveyed using changing waveform frequency. [You will find this happening more often as the fitted component types change from analog to digital.]

A typical example is the digital air mass meter, whose output waveform frequency increases with increasing air mass passing through it. With these sensors you cannot calculate the air mass from the waveform amplitude like you can with analog air mass meters. However, with Frequency counting, you can see changes in air mass flow on your screen as they happen.

How to use it

Click a channel’s Channel options panel. Select the Vertical tab and, under Frequency counting, click On to reveal the Frequency counting controls.

Typically, the threshold and input range controls can remain at their default settings. This is particularly true if you select the AC Coupling mode on the channel to ensure that the respective minimum and maximum waveform amplitudes are negative and positive to suit the default upper and lower thresholds.

An animation showing how to use the PicoScope 7 Automotive Frequency counting mode