The best commercial available adaptor i have seen has a shielded metal housing with a shielding lid over the DIP switches and all information for proper configuration printed onto it. I do not know the manufacturer, but if you have a choice take one that meets this description.
In case you are skilled to make your own adaptor, get the appropriate information on this web page:
http://www.fortunecity.de/wolkenkratzer/486/60/15pvgaada.htm
Sense pin codes are given there, too, so you can configure the adaptor to allow for the resolution of your choice. Do this only if you are used to this kind of fixes.