Teststand Basic Questions

[SK2182]

Hi,

I am new to TestStand and have few basic questions regarding the Step sequence executions.

From the forum, I got to know that the execution rate can be changed through: Configure -> Station Options -> Enable Tracing -> Speed.

But from that we don't know at what rate the execution is ran at.  In line to the rate of execution of Test sequences, I have below set of queries:

1. CAN Data is written from the device at every 10 ms. So test sequence needs to call the CAN_read function using dll at every 10 ms rate... can we specify rate of execution in Teststand sequence?

2. What is the fastest rate at which the teststand sequence can be executed?

3. Does Teststand support to execute each steps at different rate? This is required so that using CAN_write dll we can write different message ID at different rates (periodically) .

4. What is the best mechanism/feature that Teststand supports to read or write the data using the DLL periodically other than the looping (DO While, While, For... )?

I have one more question regarding the Step sequence execution -

How to stop the execution using manual intervention in Teststand?

Example Scenario: Prompt STOP should be displayed to the User and at the background periodic task be running to call function in DLL to read the data. This execution should be stopped upon selecting the prompt from the User.

An example for this scenario will really help me out.

Please clarify above queries. Thanks in advance.

Note: I am using TestStand 2017.

[crossrulz]

What I would do is use a sequence that runs in a new thread (Execution Options: Use New Thread).  In that sequence is just a loop that continuously reads the CAN data and update any file globals related to the messages received.  Your main sequence can then just use the file global values for whatever evaluations.  You should be able to use a Notifier to stop the parallel sequence.

[pulidotech]

1. I'm not sure how deterministic TestStand is.  As an alternative to crossrulz's suggestion, you can run a VI asychronously that has a LabVIEW timed loop.

2. I don't know, but if your goal is the fastest possible time, you disable tracing.

3. No.  One idea for writing at different rates would be to have an asychronous VI that constantly checks a TestStand FileGlobal that holds your desired rate.  This VI changes its write rate to match the FileGlobal.

4. I don't know of another mechanism.

5. Manual stop. You can start a sequence in a new thread or run a VI asychronously that displays your stop button. There's also the terminate execution button. 

Pulido Technologies LLC