LabVIEW 7 and Test sequence.

[ctailor]

I'm trying to write a program in the LV7 with user controllable test Sequence. The user will define a test Sequence. Some of the subvis in the test sequence are common like power up sequence. The program needs to poll for cetain signal state before running any test.

I'm looking to get an advice on the main frame/structure of the program with modular approach. I just don't know where to start! I'm pretty OK with instrument control and getting the result. Any advise will be useful. Thanks!

[waldemar.hersacher]

There is a good test sequencer from NI named Teststand. Have you made a look at this product?

Creating your own test sequencer would take you normally more time and money than the product costs.

A hand written sequencer will have two parts: a executer and the steps. The executer will load the step and execute it. Depending on the result the executer will go to the next step. A simple mechanism will be to store the sequence in a config file. Use a header to store information how much steps are in the file. Use a section named "Stepx" for each step with x from 1 to N. Each step has a key named "Typ". This is in fact the name of a VI which will be loaded and run by the executer. We use the same connector pane for all steps so we are able to call it w
ith "Call by Reference" node. We use the config file reference and the number of the step to allow the VI to find more parameters which it will use for its work. Do not forget to give back a OK status and the number of the next step to execute.
The executer has to load the configuration file, load the VI of step1 and call it and then load the VI of the next step. 0 or -1 will indicate the end of the sequence.
Use named queues to transfer data between the executer/steps and the user interface.

Waldemar

[Dennis_Knutson]

Waldemar gave you excellant advice. I started my presnet job faced with the task of either writing a new test exec or heavily modifying an existing one. I made the decision to purchase TestStand because 1) It's an excellent product, and 2) I felt that I and the rest of the test enginners should be spending their time writing and debugging actual tests and not months on a custom test manager. Out of the box, TestStand handles datalogging, report generation, and test sequencing with more flexibility than and ease of use than anything I've ever used before.