NI RS-485 card doesn't appear to generate th correct

[AlanKnowler]

When transmitting data on NI RS-485/4 cards in Labwindows 5.5 under Win2000 it appears that the STOP bit is not being generated when the number of stop bits is set to 1, and only 1 stop bit is generated when number of stop bits is set to 2. OpenComConfig is used to open and configure port. When the same code is used with an RS232 port the correct stop bits are generated. This is seen to happen on different pieces of test kit. Any ideas? Thanks Alan

[Chris_Rake]

How are you verifying the stop bit (scope, receiving framing errors, etc.)? The hardware generates the stop bits according to the serial driver. The driver gets the configuration information from an API call, which is made by Labwindows. Do you see this problem with other applications (hyperterm, LabVIEW, etc.)?

[AlanKnowler]

Thanks for your response Chris,

I accidentally posted the question on the Visual C++ forum (where you made your response) on realising this mistake I reposted on the SERIAL forum. Randy Solomonson (NI engineer) is looking at this, but please feel free to add any observation you may have.

Thanks
Alan


The discussion on the serial forum is at:

http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=137&HOID=506500000005000000A8850000&HIsQuestionPoster=Yes&HTHREAD=000034216&UCATEGORY_0=_246_%24_13_&UCATEGORY_S=0