It operates as 8 different channels. Each can be selected to do a certain task based on what it is.. Light,Sump,Skimmer,Wavemaker.. From there it brings up other option based on what it is.. example: Select Lights, then it ask if they are Metal Halide or other, Select MH and it will bring up the timer menu, then power off at certain temp.. Things like that..
They dont make RK2's anymore but DA makes newer controllers that do the same and more..