I'm not sure how, but I got it working from Python. Now I would also like to get it to work from R.

con<-dbConnect(odbc(), Driver="SQLServer", Server="localhost",Database="dbname",UID="sa",PWD="pswd",Port=1433)

results in:

Error: nanodbc/nanodbc.cpp:950: 01000: [unixODBC][Driver Manager]Can't...

What I need is step by step on setting up the driver and DSN on the Mac. I have tried countless ways with no success. Only MS SQL Server Management...