Originally Posted by PaulRivers

I'm afraid I have the Schmidt Edelux II, not actually the Cyo Premium. I don't know specifically about the senso as I never use it - I know that when I turn on the headlight the tail light automatically gets power. You could also just leave it on all the time.

The tail light has it's own standlight separate from the front light, turning off the front light leaves the rear light on until it either runs out of standlight, or if it's the topline plus you press a certain button that turns the tail light off. It comes back on automatically as soon as the front dynamo light comes on.