I am looking to purchase a controller. Wanted to go with the best and have decided to go Profilux 4. I prob will not be buying both at the same time but I am in need of a doser right away. Since I was going to go with Profilux I figured I would get there doser. If I get the 2.1 4 pump stand alone doser will it work with the Profilux 4 system when I buy it? I see they have a master and a slave. To my knowledge the slave will only work with the Profilux 4 system but can the 2.1 stand alone master unit be transformed into a slave unit when I do get the Profilux 4?