VISA Serial Break does not work

[sokol]

In my application I need to send a BREAK to wake up my instrument. I have tried using VISA SERIAL BREAK but it doesn't work. Interestingly enough that there is another VI under Functions->Instrument I/O->I/O compatibility->Serial Compatibility->Serial Port Break which works. Can anybody tell me how to use VISA SERIAL BREAK or send me a sample of code please?

Thanks a lot,
Konstantin.

[pavanb]

Hello Konstantin:

Thank you for contacting National Instruments.

Some instruments need a serial port break longer than 250ms to wake the instrument (which is the minimum time for the VISA Serial Break.vi). Do you get any error message with the VISA vi? What do you exactly mean by it doesn't work?

What is the VISA version that you have? I hope you have the latest one available from ni.com > Support > Product Reference > Drivers and Updates > Current Versions.

If you have any questions, please let us know.

-pavan b.

[sokol]

Thank you Pavan.
Does not work means I can not see any activity on TX line with a scope sending the VISA Serial Break.vi and my device, of corse, not responding. Error code is -1073807342. I/O Compatibility Serial Break.vi works fine but with a little problem probably related to my application after all. The problem is it does not keep the break duration constant from iteration to iteration and sometimes hangs at high level until the application is shut down.

Thank you,
Konstantin.