You need to perform an initial clear to return to REG mode (this will not lose any of your data).
Turn key to P mode.
turn power off at wall.
Hold down SUBTOTAL while you turn power on.
Let go of SUBTOTAL when the printer runs.
Turn key back to R mode (if display shows 'closed' you will need to log on).
----------------
If anyone is looking for a Samsung ER-5115 manual, try here:
http://the-checkout-tech.com/manuals/cashregisters/Samsung2.php
Registerman
September 2012