VISA RS232 Timeout Error

[TomDooley]

Hello everybody,

I'm developing Vi's for communication with Lawicel RS232 CAN converter.
At first I've checked the converter with hyperterminal. The instruction from Lawicel was, plug the device into the COM port, make the settings to 57600-8-0-1 None and send "V" followed by "\n" and you will receive the version number of the device.
Everything works fine, I've got it.
I step to my Labview and made a little pilot and the result was, I've receveid the same version number of the device (cool I thougth) and a timeout error (VISA -1073807339) 😞 and it tooks exact the time which is specified within the VISA resource until I've received the data.

My questions are, does anybody know why I get the error and why I takes so long until the VI response?
Within hyperterminal the response time is less than 1 second?
Is there a alternative for VISA which I can use also on RealTime systems?

Thank's

[JoshuaP]

Since you have Termination Enabled, I would guess that your device isn't returning with a termination bit or it isn't '/n'. Try setting Enable Termination to False and then set the read count to the exact number you expect back and see if it immediately returns. I would then increase the count by one and try to read again to see if there was a termination character. To see the termination character you will need to change your indicator to '/' Code Display.

-Josh

[TomDooley]

Hi Josh,

my device returns "/n". I resolve the problem by using the "property node vi" between VISA write and VISA read. But I don't know if this vi runs under RealTime target also!
I'll make some further test and comming back soon.
Thanks!

[ibl-hh]

Use \r (only CR) as termination char then it works fine...