Portal 2: Creating Moving Panels

How do you create moving panels? I tried following the tutorial from the Valve Developer Community but when I tested it nothing happened and the arm stayed still. Any ideas? Thanks.

I think I may have found a part of the issue. I looked at the tutorial again and I used something other than a logic_auto entity. I remember the reason was because it was supposed to be set to OnMapSpawn so I thought that the panels would move whenever the map loaded.

So I assume that you can still trigger the animation with a different trigger?

Also, is it correct to say that the logic_auto will not trigger the animation?

Some more things I'm unclear about:
Here is the link to the tutorial I'm using if you need to see what I'm writing about:
https://developer.valvesoftware.com/wiki/Panels

1) In the logic_relay they said to create an output with a parameter of (ANIMATION NAME) and they gave a list of some models with a panel attachment name. Is the panel attachment name the same thing as the Animation name?

2) I noticed that the logic_relay has a name of relay_panel1_animation, but it is not being called by any other entity. So what is the purpose of its name?

3) What exactly needs to be triggered in order to start the animation?

4) Also, how do you tell it in which direction you want the panels to move if it moves with a certain animation?

Thanks for you answers!