The duty cycle measurement is a procedure where the ratio between the high (or low) pulse of the signal and the period is measured. As was previously stated in the encoder tutorial, the decision to use X1, X2 or X4 mode depends on the quality of the encoder and the encoder electronics. The same encoder as was used for the Encoder tutorial will be used to measure its quality.

For this measurement we need to set the Period, pulsewidth, duty cycle mode . If this mode is not available, then the counter does not support it. Either it is a super-counter pair (only even counters of the Orion have this mode) or it is not an Orion card.

Channel setup

Then we can directly select the Period, pulsewidth, duty cycle and also the frequency output channels. The counters are set automatically for this operation.

Now let's look at the duty cycle measurements. The upper graph shows the period and pulse-width of the signals. In the lower graph, we can see the duty cycle for the few rotations of the encoder. We can observe nicely that there are some points where the encoder has a slightly larger error than in the rest of the data. The value there is approximately 0.49, so this means that the encoder mode X2 will have around a 1% of the error.

Analysis - Duty cycle measurement