If you have older software on your Net3 Gateway (pre v7.0) and wish to set a dimmer double for your ports on a Net3 Gateway, please follow these steps.
Steps to Solution
First you will open GCE.
Go to File at the top and choose Preferences.
The dimmer double offset is set here. This is the offset it is look for from the network device sending it sACN. If your console is set to 256. If your console is set to 20000 set this to 20000.
For the port you wish to configure to dimmer double, you need set it to the universe number and then DD, so for Universe 3 it is 3 DD:
When you hit enter it will show the offset: