port config error

[stahl]

Hello,

Our laptop is communicating with a Eurotherm 818 temperature control unit through the serial port. The program (Labview 7.1) uses VI's downloaded from the web, i.e. EI BYSINCH Read.vi and EI BYSINCH Write.vi, and obtains temperature and power measurements from the Eurotherm in real time. MAX says serial port is working properly. OS = Windows XP

PROBLEM: After around 2.5 hours (fairly consistently), the "Port 0 Config Error" occurs, and the program cannot be continued. I have determined that the error originates in the "Open Serial Driver.vi" which is a subvi in "Serial Port Init.vi", which in turn is a subvi in "Lab Serial Port Init.vi". (The first two vi's are Labview library files).

ATTEMPTS TO FIX: I have viewed a thread with a similar problem http://forums.ni.com/ni/board/message?board.id=170&message.id=76152&query.id=21947 for advice. I found the error handler and have tried creating loops to retry opening the driver, as well as closing it and then trying to open it again - with no success, i.e. Internal Error occurs. I have also been experimenting with the "force re-open" control in the "Open Serial Driver.vi", with no success as of yet.

Any ideas on solving this issue would be greatly appreciated.

Thanks very much,

Ian

[mfitzsimons]

Ian,

Sounds like your program is not structured the way I like to interface the serial port.  There should be one call to serial init.  After the serial port is open save the reference and use it to read and write the serial port.  When the program is complete call serial close once.  This will take care of the issue.  I have serial devices that I talk to for months at a time.  Yes, months using Windows XP.

Matt

[Dennis_Knutson]

Where did you download the driver from. NI doesn't list one for this model. Based on the names of the serial functions and the port number, it sounds like it was originally written with the old and obsolete serial drivers. LabVIEW 7.1 will convert these to use the existing serial interface which is based on VISA but it's possible that a bug has crept in due to the conversion. Also, how are you using the driver. Normally, you would call serial port init once in a program so I don't understand why the error would point to this VI after any time other than the start. Could you post the driver llb and the vI you have written?