Most DLR stations have 'hidden' Oyster card readers - however, the responsibility to find it rests with the passenger.

In terms of the Penalty Fare, my experiences are that it is not always offered. Typically if you don't have the means to pay it there and then, or they cannot confirm your identity or your get mouthy, they will prosecute. That's typically a fine of a weeks salary, costs of about £145 pounds, the cost of the fare evaded and a criminal record.

Make sure you find those Oyster Readers, regardless of how long it takes is my advise.