As long as your iPads are at the same physical address, multiple iPads can run off the same account configuration. The layout of devices associated with the same location will be identical.
Each iPad can be given a Device Name, like 'North Lobby,' 'Loading Dock,' or 'Second Floor.' Each check-out and check-in will be associated with that iPad and that Device Name, ensuring it's easy to tell who entered what door; you can view this information and filter by particular devices on the visitor log.
The notifications sent to contacts will display the name of the iPad that was used; this ensures that your contacts know exactly where to greet their guests.
To name your iPad, touch the top middle of the home screen for a few seconds, press "Device Settings," and enter your password.
Once you enter your password, you can enter a unique Device Name. Once finished, tap the < to save and return to the main settings screen.