IPVMU Certified | 05/28/15 11:45pm
I would incorporate traditional access control, but unlock the door on a normal schedule. Then configure a 'lockdown' button for emergencies like you mention.
That way it becomes straightforward to include life/safety devices like RTE or pushbuttons that keep your solution legal and safe.
Is it just two doors?
Are they double-doors?
We do this routinely for a customer. We add a larger manual button at the front desk that is plainly marked "Override". The personnel are instructed on how it works and why. Several years ago they had an office in the Chicago Merchantile Building, a guy gets on the elevator and stops at a few floors, gets off and sprays gunfire. They could not lock the doors because of the schedule. Now they can, and it has become a standard.
Push it once, it locks, push it again it unlocks. In the locked position, it overrides the door's state and forces a locked state. It stays that way until it is unlocked. You can still exit, but you cannot enter. It is just a programmable relay on the access board.
I forget the part number (at home now) but ADI sells them in a pack, several lens colors to choose from, make your own nomenclature.