VISA: (Hex 0xBFFF003A) using a RS232 to USB converter

[Dennis_Dutoit]

Hi, i am trying to read a pH meter and it's connected to my computer by USB using a RS232 to USB converter. NI-MAX recognizes the instrument but when i try to read the instrument in the testpanel i've got the time-out error. When i read the status byte it gave me the following error VISA:  (Hex 0xBFFF003A) Unable to start operation because setup is invalid (due to attributes being set to an inconsistent state). I've looked into the atributes and saw the following error VISA:  (Hex 0xBFFF001D) The specified attribute is not defined or supported by the referenced resource. the pH meter is a simpel desktop device with the following specifications: baud rate 9600 8 data bits ans 1 stop bit no parity or flow control.

[Dennis_Knutson · Accepted solution]

Why try to read the status byte? It's not a GPIB based instrument is it?

What attribute? I asked in your original post to attach a screen shot of MAX. Why should someone have to guess? I suspect that attribute to only apply to NI serial devices and is irrelevant as trying to read the status byte.

Check to see if you are using the correct type of cable and check to see if you are appending the correct termination character. You also do not mention if you are writing anything to the port or just doing a read. You also don't mention the vendor or model number of the meter.

[Dennis_Dutoit]

Thanks, i found the problem. Apparantly other student have taken some of the apparatus from the reacor and put it back and used the wrong cable.

thanks for being so patient.