For quick video showing how to add new controllers:
https://deif-my.sharepoint.com/:v:/p/pla/ER22_nZZy7hGuJgds1O-qPkBZJGdlY4cRohAFS9fGCLVmg?e=DvzJWO
Press the Settings button, press devices 
Go to the top right corner and press the 3 dots
press add device
Choose a template, if you are connecting to an AGC of some kind you could use the "ML2 controller" template as that will already have some addresses added
Fill out data, the IP is the IP of the controller itself. If you want to add new modbus addresses, press + Add New under the Tag list.
press save when you are done.
If you think something needs fixing leave feedback here: