Save Test Time by Automating With Sequence Looping (100 Things #49)
Save both sequence development and test time by using sequence looping to run repetitive test elements in a sequence. This is valuable for any kind of test where you need to repeatedly change a test parameter, for example, increase stimulus level by 5dB and re-test, make measurements at multiple fixed frequencies or frequency sweeps, or even move a turntable and re-measure a device to create polar plots.
Automating SoundCheck Tests with Sequence Looping
Learn More About Implementing Sequence Looping
Check out our easy-to-follow tutorials on sequence looping.
More information is also available in the SoundCheck Manual.
Video Script: Save Test Time by Automating With Sequence Looping
Sequence looping is a useful technique that saves both sequence writing time and test time by running repetitive test elements in a loop within a sequence. This is valuable for any kind of test where you need to repeatedly change a test parameter, for example, increase stimulus level by 5dB and re-test, make measurements at multiple fixed frequencies or frequency sweeps, or even move a turntable and re-measure a device to create polar plots.
Using sequence loops instead of hard-coding each sequence step offers many advantages. It keeps your sequence shorter and easier to read, and the sequence logic is clearer. It’s much faster to program and easier to update, because if test parameters change, they only need updating in one place. In many cases it removes the need for manual user-input while the sequence is running, making your test much faster. There are many other benefits too. Data in the memory list can be automatically named using the loop index, for example, by appending data such as stimulus of frequency level to the curve name, and you can even use loops to prompt an operator to change device settings between measurements.
Here’s a simple example where we use a basic loop to increment the stimulus level by 10dB each time and plot all the measurements on the same graph. You can see it looping through the sequence, automatically naming the curves and adding to the memory list, and plotting them on a graph.
Where it gets really useful is when you start to apply sequence logic. Using commands such as “jump on pass” and “jump on fail” you can determine the next steps in the sequence based on the results of the measurement. For example, if the device passes the test you can increment the level and re-measure, and if it fails you could decrease the level and repeat the test, or end the test and produce a report. You can also nest loops for more complex test procedures. You can see this being put to good use in our AES-75 test sequence. This determines the maximum SPL of a loudspeaker using multiple loops and logic to repeat a measurement at different levels, and compares the results to a baseline measurement to determine the next sequence step.
SoundCheck’s looping capability even extends to working with previously saved data, where it can iterate through a set of files in a folder, applying post-processing calculations, statistical analyses and more, and displaying the results in a user-defined way. This is a standard feature in SoundCheck, and its been available in all versions for over 20 years!. Check out SoundCheck tutorial #7 on our Youtube channel if you want to learn more about how to use this useful feature!
