Activating line follower from standby mode

I'm using a MGS1600GY with a SBL2360.
I understand:
I can use a PC to write a map for the line follower
I can load the map into the line follower
and then disconnect the PC.


My question is what makes the line follower begin its journey.

Does it start at power up?
Is there an electrical "start signal"
Something else?