Central operating and display unit for 4 doors with escape door controls with TS bus network.|Processor-controlled central module with:|Buzzer as acoustic collective fault message,|Button for alarm reset,|Two relay contacts for forwarding status messages,|LED for operating display,|Three LEDs for status display,|Button for checking the LED displays,|Key switch for enabling/disabling the control buttons for controlling the doors.|With operating and display elements for four doors each with:|Three LEDs (red, green, yellow) for optical door status display,|Two buttons for locking/unlocking or resetting.|Can be expanded with panel module extensions up to approx. 20 doors