Denver Instrument TP-12 Balance with VISA in LV 2013

[4Strings]

Hello!

I am having some issues with a Denver Instrument TP-12 analytical balance.

I have set up the balance and made sure that all the VISA settings match in LabVIEW.

I do manage to read accurate weight from the balance, and the read buffer works correctly, but every 30 seconds or so the read buffer gets filled with gibberish (random non-numeric characters) and so the numeric data (after converting from String to Numeric) is read as 0.

I contacted Denver Instrument (now Sartorius) and was told that the problem probably lies in LV.

Attached is the VI that I am using as well as screenshots of the read buffer when it reads the gibberish.

Any advice as to why I am having these weird reading and what I can do to either prevent them or a method to have the numeric data ignore the spikes in the reading would be GREAT!

Thanks-in-advance,

 4Strings

[Mathieu_T · Accepted solution]

Hi,

In order to know if LabVIEW is the culprit of this behavior, it might be very helpful to use this architecture :

and tell us if you see the same behavior.

Regards,

[4Strings]

It worked! 

Thank you SO much!

-4Strings

[Mathieu_T]

Thanks for your feedback !

Producer/Consumer is one of the most powerful architecture for data processing/logging :

     - One loop (one process) to acquire datas

     - One loop for processing/logging

By using this architecture, you are sure to remove 99,9 % of acquisitions issues.

Cheers,

[4Strings]

Thanks!
How would I log more data streams from other sensors (from temperature probes, condutivity probes, etc.)?
Do I just add separate ques for each of them in the producer loop, or can I add them to the first que?

Thanks again,
4Strings

[EccentRick]

Hi 4Strings,

Mathieu_T had a great advice when he recommended the producer/consumer loop. If you want to pass multiple datatypes with the queue structure, I would recommend grouping the data into a cluster or an array, since a queue can only handle one data type (e.g. a cluster containing a string and a double). 

There's a bit more information on the producer/consumer loop here: http://www.ni.com/white-paper/3023/en/