M355 is the gcode for toggling case lights on/off, but you'll need to check if your firmware supports it. Take a look here: http://reprap.org/wiki/G-code
Reason I ask is to see about adding it to the ending script section so when print is finished it could turn out the light. Haven't had a chance to try it yet.
Has anyone got this working? It must be possible as ReplicatorG supports it. I'd like to switch off the lights as I have a webcam monitoring print progress and the lights cause it to over-expose.
As has been said earlier in the thread, if your printer and firmware support a command to turn lights on or off, you can add the relevant command into your ending script. S3D has the capability to allow commands to be included....so if your printer will accept an instruction.....then S3D will be able to give it! You just need to find out what it is.