I think Mettler normally provides the information, try contacting a local office and ask them if you can have the information you need. It's normal to allow people with other software to be able to interface with a pH meter, so I think the chances are quite good that you'll be able to get the information direct from Mettler.
Hope this helps.
Shane.
Using LV 6.1 and 8.2.1 on W2k (SP4) and WXP (SP2)