The slave connects via PAB (ethernet) cable from one of the open ports on either the KH Director or Master Doser. From there: open the GHL app/myGHL website and connect to your Master doser. Click on the 3 line icon and select System in the menu. Then scroll down as necessary to click on the "Assign and configure connected PAB-devices" After assigning the new doser, click on the gear icon and verify that the pump start numbering is 5, 9, etc. That is it. The doser pumps will show in the rest of the system and can be configured to your needs.