Parallel model questions

[Hoss183]

I have a few questions about how to implement a parallel model multi-socket test.

So, we have a test board which is controlled by USB (1 per board).

I have developed a VI based test sequence, that runs fine in a single mode.

Now i need to rconfigure this to use 2 sockets to run 2 iidentical test simultaniously (asynchronous)

A few things are unclear to me in the implementation:

1. Are the variables common to the 2 instances, or separate? For instance i use a local which is the handle to the comms for that board, but do i now need a different local variable for each socket? If yes, i dont see how that would be implemented, because the variable is specified in the sequence.

2. How to define constants that will apply only to one or other of the sockets (i.e. the board usb port)

3. Is it really multi-threaded? i.e can i call the same VI in 2 instances?

[RayFarmer]

Hi,

1. Do you have one resource or you multiple comm ports?

2. You can use the Socket index to get the correct data, off course you would have to use an array to hold this data. If handles are not from a shared resourse then there is no need for any special consideration. Each Socket will be totally independant of each other. Its only when resourses are shared that you need to make sure each socket is not trying to use it at the same time.

3. Providing VI are re-entrant then you can multiple instances of a VI in memory. Otherwise you would have to use synchronization so that you can share resourses.

[Hoss183]

Thanks Ray

In fact i found your reply in this thread http://forums.ni.com/t5/NI-TestStand/Parallel-Model-using-Multiple-Com-Relay-Cfgs/m-p/1000662 and have a semi-working solution.

[RayFarmer]

ok that's great

[dug9000]

1) Local variables are separate per testsocket, so are FileGlobals by default (though there is a setting in the sequence file properties dialog box to share them), station globals are of course shared.

2) See Ray's answer.

3) See Ray's answer.

Hope this helps,

-Doug