NI 2 port 485 wire mode in Windows 7

[rgblair]

I have an older NI 2 port RS-485 PCI card (c. 1997).  Recently I neede to configure port 1 for 2 wire and port 4 for 4 wire.  Using Windows 7 and the latest version of Measurement and Automation Explorer, I could not change the wire mode.  The whole section was greyed out. I put the card in a Windows XP machine running the newest Measurement and Automation Explorer and I could set the wire mode.  

After uninstalling and installing the serial drivers and the card in the Windows 7 machine I still could not set the wire mode via Measurement and Automation Explorer or even programmatically.  Through sheer dumb luck I looked  at the com ports in the hardware manager and found an advanced configuration button.  A window with a pull down menu allowed me to set the wire mode and it worked.  

Is this the way 485 pci cards on a Windows 7 machine work now?  I am posting this because I had a heck of a time finding the setting and hopefully someone will be spared some frustration in the future.

[Travis_Ann_N]

Hi rgblair,

Is this the card you have? If so, it is was created with for FULL compatibility for Windows XP/2000/Me/9x/NT. However, you should be able to use NI-Serial 3.6 to communicate with that card in Win 7 (indicated by this NI-Serial Driver Support sheet). 

Regards,

Travis Ann

[JasonSmith · Accepted solution]

The settings are grayed out because they are only available to users with administrator access. On Windows Vista and Windows 7, you should right-click the Measurement and Automation Explorer icon, and select "Run as Administrator."

-Jason S.

[rgblair]

Thanks - I tested this solution and I can now change the wire more.  I must have found a security hole.