Fading a layer with artnet

I am totally new to this stuff, but I am trying to make a mini media server. What I want to do is create 2 layers of output. I want to select the image in each layer and want to fade between them. I have found the built in dissolve and fade modules, but I want to fade in time with the lighting cue thru art net. I am stumped on how to control opacity via 0-255 or 1% - 100%. All the controls I find are from 0-1 with decimals in between. Any help would be greatly appreciated. The only work around I can find is to use the dissolve module and send it data for time and which images to crossfade between. This is not ideal though.

Thanks again