Official comment
Please see KB955 for the latest information https://support.echelon.com/hc/en-us/articles/204937174
The OpenLDV Network Driver is used for i.LON 10/100/600 RNI, PCLTA-20/21, PCC-10, SmartServer, and U10/U20 network interfaces.
The i.LON 10/100/600 RNI, SmartServer, and U10/U20 are supported on 64-bit Windows. The PCLTA and PCC-10 are only supported on 32-bit Windows OS.
Make sure the PCLTA/PCC-10/U10/U20 are not plugged into the PC when installing the driver.
To find the latest Network Driver go to www.echelon.com/support, click Software Downloads, type "openldv" in the search text field and hit the enter key.
OpenLDV 4.0 was the latest as of July 2015.