When a C-Bus Unit is shipped from the Clipsal Integrated Systems factory its Unit Address is set to 255. If you physically add more than 1 new unit to a Network at a time a process known as "Unravelling" must be take place.
The Unravelling process ensures that each unit on a Network has a unique unit address. If two or more units share the same Unit Address they cannot be programmed, this will cause bad karma.
Each time the C-Bus Toolkit scans a Network it first does a check that no duplicate units exist. If you haven't yet scanned a Network you should read the tutorial on scanning a network here.
So, add your shiny new units to your Network and scan the Network. The Toolkit will do its Duplicate check and determine that more than 1 unit has been found at address 255, you'll see this message appear first:
Press the "Yes" button to start the Unravel process.
Toolkit will unravel each of the Unit Address that it has determined that duplicate exist at. You will see this Dialog that shows the unit addresses involved. You can choose to allow Toolkit to unravel each of the addresses or refine the operation by 'unchecking' addresses that you might not want unravelled (if you like living dangerously
As you can see, only the 255 Address has duplicates. Press the Unravel button to start the Unravel process. Toolkit will move the first Unit it finds at 255 to the first available address, it will then repeat this process until it finds no more units at address 255.
Press the Close button to dismiss this Dialog. Toolkit will then complete the Network Scan and you can be confident that there's no 'hidden unit, crouching problem' issues waiting to trip you up.