I’m looking for some help parsing string data. I’m playing with a cheap gas sensor, its talking (sending commands is hit and miss but once started it streams ok). I’m trying to graph the CO concentration and write the data to csv. I feel I must be missing some basic knowledge on VISA somewhere, I was expecting simple csv strings of data but my last attempt ended up at a 547mb csv. I was hoping that using line feed termination meant I had blocks of 65 characters to play with but I'm struggling to understand whats really going on. If someone can point me in the right direction I would be most grateful. P.S. I save the vi in 2017 if anyone need a earlier version please just ask

Hi Si, I took another look at the latest VI you uploaded. I have a couple of questions and then some minor observations. I'll number them to make it simpler to refer to specific points (not to imply importance): What's a typical value for "return count"? Does it stay at 65? What's a typical value for "Serial Settings:Number of Bytes at Serial Port"? Is it fairly constant or changing a lot? Is it less than "return count" systematically? (Is it zero or close to zero systematically?) Have you tried just waiting repeatedly (rather than repeatedly resending the "c" command) for the first loop? Can you try appending a Line Feed character to your Write commands (like below, after numbers) You can create an indicator for the Enum (rather than writing a string out of each case). Alternatively (if in future you need a string) then Format to String accepts enums and will output strings (image below) Does it behave the same if you remove the VISA Clear at the beginning? Or perhaps replace it with a Read command (maybe after using Stall Data Flow for a couple of seconds as you do between the loops)? Point 4 Point 5 Regarding the possibility of a broken converter - it's certainly not impossible, but I haven't had it happen to me that much (once from maybe ~10 $10-$15 adaptors? Numbers from the top of my head, may be horribly inaccurate). I have seen it reported on the forums though... (probably the same posts you've been reading) Following the writing of my post, I'd suggest taking a look at #4 first.

LabVIEW

VISA string parse problem understanding

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Problem update:

Cbutcher sage advice has been spot on 🙂

Everything now works perfectly and I have learned a lot from all the help.

Even the occasional random error was traced to the Windows 10 driver. Well when I say traced all I did was run the application on a Windows 7 machine, hey presto it ran overnight perfectly.

So may I offer my sincere thanks and gratitude

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