This seems useful.... from another post.
I've gone back and done some more investigating on this.....
When I choose fixture 1 I have access to the first 8 channels. When I push the bank button, then I have access to 9-16. If I address my second fixture on channel 9 (wich would be address 9) I can control the next 7 channels for that fixture.
When I choose fixture 2 (That address is 17) again i have control over the next 7 channels. When I hit channel bank, i now have access to the next 8 channels, but if I address a fixture on 25, that is the first channel of that bank (9) again I have control over that fixture.
What this says to me, each fixture has 16 channels but I've essentially split that so each fixture has 8 channels, thus 16 fixtures. This only works if your fixtures only use 8 channels. Which mine only use 8.
I hope maybe this is right and may help some people out.
cheers.