Systems and methods of accessing a control system are provided. Some methods can include a mobile device transmitting a wireless entry request signal to a tag device, the wireless entry request signal including a mobile device identifier and a system identifier, upon receipt of the wireless entry request signal, the tag device comparing the mobile device identifier and the system identifier with a list of authorized identifiers, when the tag device determines that both the mobile device identifier and the system identifier match an entry in the list of authorized identifiers, the tag device transmitting a data file to the mobile device, the data file containing a door identifier of a door, and the mobile device transmitting an access request signal to a controller for use by the controller in unlocking the door, the access request signal including the mobile device identifier, the door identifier, and the system identifier.
