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Arduino Uno+Labview 8.5

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A good way to debug is to use I/O Trace. This is turned on in MAX. Capture the traffic when sending the command from MAX and capture when you use the example VI.
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Message 11 of 31

Thanks for this suggestion. Please have a look at the IO trace attached. 

Lines 1-9 lines are the trace of using NI MAX. 

Lines 10-14 using my vi sending just the command


Is there a difference between ASRL4::INSTR and COM4?


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Message 12 of 31

Oh Sorry the trace file cannot attach. 

One difference is in the name. But I get only COM1 COM4 LPT in the options for the resource name. no ASRL.

I will try to paste the trace if needed.

Message 13 of 31
ASRLx is the canonical VISA Resource name and Comx is the alias. There is no difference here.
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Message 14 of 31

The trace file is attached. First 2 lines are from executing command on NI-MAX and others are on running the attached vi.

Can somebody please tell what needs to be corrected? 


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Message 15 of 31
Sorry, I don't see anything wrong. Are you sure the serial configuration in MAX and in the VI are the same? You can actually skip the configuration in the VI and the MAX set-up will be used. Your VI would then have nothing except a VISA Write.
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Message 16 of 31

Thanks Dennis. Before this, I had made a vi with only VISA Open, Write, Close. It didn't work. So tried to use config.

It is not responding to IDN query with VI but is respondin to IDN using MAX with return count 6. 

In case it helps, I can't find visaconf.ini even after showing the hidden files and folders in the location C:\VXIPNP\WinNT\NIvisa. But COM4 is opening up on MAX as ASRL4 so that shouldn't be a problem. I can't think of anything. 


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Message 17 of 31

Just one small comment.

The "Return count" out of VISA has nothing to do with what your device is returning to a given command.



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Message 18 of 31

I used a Serial port monitor. Ran the command on MAX at 13:52, closed MAX at 13:53.

Ran the VI at 13:54:01.


RTS control signal is cleared as well as 'request cancels the specified requests' before closing the com port all at the same instant 13:54:01!

How do I prevent this clearing of buffers and cancelling of requests before vi close?

The port activity can be seen in the txt attached.


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Message 19 of 31
You just don't have millisecond resolution. The operations are not taking place at the same time.

The operation in MAX sent idn and not I5000 but the LabVIEW sequence does show the cr and lf being sent.
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Message 20 of 31