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serial port

This is a generic question about "test system architecture" in terms of how you develop your LabVIEW VIs etc. to work in a Teststand environment...

 

In a test system there is usually some central computer (PC) controlling numerous other devices (test equipment) which are all connected to it in some fashion.

 

In a simple application a Teststand "step" (i.e. action of numeric limit test) could run a VI which:

 

opens a serial port

writes

waits

reads some data

then closes it.

 

.. and returns to evaluate the numeric limits/results.

This is not a problem to implement. I think this is called a "connectionless" link.

 

In a system where the piece of test equipment (or even the DUT) is constantly communicating i.e.

 

streaming data

or a periodic heartbeat message 

 

... where the PC cannot be so slow on the serial link...

 

What is the best solution/architecture?

 

My impression is that you would create a serial communication VI (which is always running) and start it initially from an asynchronous VI call at the start of the teststand sequence. 

Communication would then occur between Teststand <>LabVIEW VI, using queues.

you could define the rest i.e. messages and data structure/protocol yourself.

 

Is this correct?

 

I would really appreciate it if someone could point me in the right direction in terms of example code/application notes...

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That is how I've done my test systems.  Usually have VIs that react to my queue data as part of a test step.

 

I had to do this with a serial port as well as LabVIEW FPGA interface.  Haven't had to worry about any instruments constantly sending data.


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