Go to the Mill Manual pdf on the Haas website, here is a link, search the pdf using M-FIN or user M function and you will find some description of what serviceman is referring to. Also go through the Haas Mills forum and you will find some threads about these, I posted some pictures of the location of the contacts in one of them.
http://www.haascnc.com/customer_serv...mc/96-8000.pdf