How to use an oscilloscope to achieve automated testing?

Recently, a customer encountered a problem. Their company produces low-power motors. The motors produced have to be measured one by one with an oscilloscope. This is too inefficient. They want to test automatically on the production line. This can actually be achieved. The oscilloscope has a template test function. When the template test fails, the oscilloscope will send out a pulse signal. The pulse signal is then connected to the PLC controller to automatically separate defective products. The specific operation is as follows

1. First of all, the oscilloscope must have a filtering function. If there is no filtering function, you cannot use the template to test the motor, because the motor waveform is relatively messy and contains a lot of clutter signals. As shown in (Figure 1):

figure 1

The picture above is the original waveform measured by an oscilloscope when the motor is rotating. We can see a lot of spikes, which are a lot of noise. Generally, motors will have a lot of such interference (the brushless motor has less interference). We have to filter out these noises before performing the template test, otherwise the template test cannot be performed.

2. After the oscilloscope turns on the filtering function, the effect is shown in (Figure 2):

figure 2

3. Start the template test. As shown in (Figure 3):

image 3

The above picture is the interface of the template test. If the waveform of the motor is irregular and the amplitude of the waveform changes greatly when it is working, the waveform will touch the gray area and the test will fail. At the same time, the oscilloscope outputs a pulse signal through external triggering. We can connect the pulse signal output by the oscilloscope to the PLC controller through the BNC cable to realize automatic testing and separate the defective motor. We can also set the oscilloscope to make a sound, or take a screenshot and save it.