In this part I’ll continue looking at some of the other step types, specifically:
- a sequence call and passing a parameter to a sequence.
- a statement
- a message popup
- the property loader.
Creating a sub-sequence
One way to build cohesion into a TestStand sequence is to make the separate tests (or whatever logical division you are using) into their own sequences. You can either have a sequence file call other sequence files or you can create a subsequence that is called from a main sequence. The difference between the two is that subsequence is not visible in file directory, it’s just stored in the main sequence.
Starting with the TSBasics2.seq sequence file from part 2 and renaming it TSBasics3.seq, I’ll show how to turn the Sine Amplitude and Frequency Test into a subsequence.
Figure 1 shows the sequences pane, right click and select insert sequence.
Cut and paste the steps from the MainSequence into the new AmplitudeAndFrequencyTest sequence. At this point this new sequence is still not called, so we have to drag a sequence call step from the Insertion Palette into the MainSequence and set it to call the new AmplitudeAndFrequencyTest sequence. Rename the sequence call, as shown in Figure 2, right click and select Specify Module. Then, click on the Use Current File check box and select AmplitudeAndFrequencyTest from the drop-down list as shown in Figure 3.
Message popup and passing parameters
First, let’s use the Message Popup step type that will allow the user to set the stimulus frequency. This message popup will set the users input to the local variable called StimulusFrequency. Then we will add a parameter to the AmplitudeAndFrequencyTest subsequence called SetStimulusFrequency which will be passed to the VI for testing and we will see the result on the report.
Add the message popup step type (Figure 4)
Using the Property Loader
First drag a Property Loader step type into the Setup step group of the main sequence. This is the perfect type of operation to put into the Setup step group of the as it fits well into the logical category of setup.
Since we already have all are limits setup in the sequence file and sub-sequence it’s easy to create the limits Excel file. Click on Tools -> Import/Export Properties…
On the Source / Destination tab select file and Excel, on the Properties tab select all sequences and click the limits button. Click Export, give it a file name and click done. See Figure 12 and 13.