VISA Serial communication - Errors

[Phil747]

Hi,

I'm communicating to an instrument with a serial port using VISA Serial in LabVIEW 7.0. I have to say I also use a RS232 cable (USB-Serial) 'cause my laptop doesn't have a serial port. At an average of 1 time over 10, I get an error. There are 2 different errors I've gotten till now. I've attached pictures of the dialog boxes I get when an error occurs. Can anybody help me find why I get these error? Thanks

Phil

[ryank]

The second error generally occurs if you have one of your serial settings off from the instrument's settings (stop bits, parity, etc.). It could also be caused by a problem with your converter. I won't name any names on a public forum, but I have run into at least two usb-232 converters which are really bad. You might try running your program from a desktop with a serial port and see if you see the same problem. As for the first problem, it might, once again, be caused by the converter (bad connection causing windows not to recognize it sometimes, etc). This error could also be caused by a programming error (i.e. closing a reference before it is configured, passing a null reference into the configure (this second generally happens if you are using a state machine
or event structure with the "use default if unwired" option for your refnum terminal, never use this option for refnums or errors).

Regards,
Ryan K.