I know this may sound like a silly question but my Judge Dredd globe switch #1 is not working. This is a U shaped opto. I have interrupted the signal with a card but it doesn't open in the switch matrix. I'm getting voltage to the switch. I decided to swap out the switch but I can't figure out the orientation of the opto. On the top of the switch, the left side Has a + on the top, and E on the bottom. It also has an arrow like this -->. On the right side it has an arrow, D on top and + on bottom. Also has an arrow going the same way. -->

I would just go ahead and try it one way but I'm worried it could do damage.

Awesome, thanks. Instead of S it had a D on it, which I assume stands for detector. I double checked by putting my volt meter on each side. The side that tested like a diode gave me the indication it was the emitter side. Thanks again.