Bought new Pixie 2s

[trooperblazer]

So for this year I purchased 5 pixie2s.  These will be powering my 10 16ft arches.  How do I know which is port 1 or 2? Or do I need to open the case and then label the dongles?

[Mr. P]

If you hold the controller up and look directly at where the strings go into the controller the string on the right is one, the string on the left is two.