LabVIEW Programming

[teddy_aua]

Thank you very much for your reply. I also want to know whether LabVIEw provides a VI that converts hex values to IEEE 754 floating point numbers? If so, what VI is that?

Thank you

[piggieq]

Hi Teddy,

There is a thread in the forum that exactly solves your problem.

Please refer to Message 2 of http://forums.ni.com/ni/board/message?board.id=170&message.id=204237&requireLogin=False

Best regards,

Guo Min

Applications Engineer

National Instruments ASEAN

[teddy_aua]

Hello,

I am trying to read data from two sensors connected to two seperate ports (COM 6 and COM 5). I am using the LabVIEw VISA funtions. The program works for sometime, but then reports and error with error code 1073807339. I looked it up and found out that this means a timeout. I would like to know how to reduce the time the program stalls on this error. Will reducing the timeout reduce the stall time??

Also, I am using the two VISA reads under the same while loop, will this be a problem as well? Or is there a more appropriate way to stream data from two com ports synchronously?

Any help is much appreciated.

Thank you

[RavensFan]

Reducing the timeout will definitely reduce the amount of time the program stalls before the timeout is returned.  But that still won't solve your problem as to why you are getting a timeout.

You'll need to post your VI so we can look at it to be able to comment on how to improve it.

[teddy_aua]

Hello,

Thank you for your reply. I have attached the printscreen of my program. I am using one while loop to acquire and display data from two sensors connected via two Com Ports. Kindly let me know if there are better ways to synchronously receive data from two ports. Also, I would like to know how I can reduce the stall time, or any ideas on what should be done if data is not available from one sensor during streaming.

Thank you

[newbieLabview]

I am new to labview... i just wanna ask is it possible to convert the bolean data (true or false) into string?

[MikeS81]

Hi newbieLab...,

yes it's possible. One way is to use the "select" function and connect a string for true/false to it.

Mike

[nathand]

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newbieLabview wrote:
I am new to labview... i just wanna ask is it possible to convert the bolean data (true or false) into string?

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Use "Format Into String."  Wire in your boolean value and you'll get a string ("TRUE" or "FALSE" ) as the output.

EDIT: I don't suppose anyone knows how to tell the forum display quotation marks followed by a close parentheses as text, and not a silly smiley?

Message Edited by nathand on 01-20-2009 08:04 AM

[jcarmody]

You can be experienced with LabVIEW someday, and you'll wonder why you chose that user name.

[RavensFan]

Newbie Labview,

It looks like you highjacked this thread from Teddy_aua.  You should have started your own message thread.

Teddy,

You probably should have started a new thread and put in a more descriptive message in the subject line.  Every thread in this forum is going to be about "LabVIEW programming" and your original messages were back in September about cursor positions on XYgraphs.

It is hard to troubleshoot your code by way of a partial screenshot embedded in a pdf file.  The problem could be in one of those ASPP subvi's.  How does this device communicate?  Do you send a command and wait for a response?  Or does it just stream data continuously?  Do both serial ports wind up with the timeout error or just one?

If you disable one half of your communication code, does the other half communicate properly for a long time, or does it timeout as well?  While it is probably a good idea to separate each serial communication code into two separate loops (much of that code should really be placed into a subVI since it is duplicated), it shouldn't really have problems if both communications loops are working well, however a hiccup in the communication of one serial port would cause delays in the reading/writing of the other serial port since they are in the same loop.  Perhaps that sets off a chain reaction of errors. A baud rate of 115200 is rather high, are you sure the data can be communicated reliably at this rate?

All of this can't be debugged just from a screenshot.