Interface unit to connect Call system with other existing patient-nurse systems or with other external alarm systems (e.g. building management systems, fire detection, etc.) by means of configurable Input/Output. This allows the Call system to notify an external technical alarm (i.e to BMS), or even to use the nurse call system to easily inform about an incoming external tehcnical alarm from a 3rd party system. Up to 4 inputs and 4 open-collector output circuits are available. The I/O interface is commonly used as a control unit for managing group signal lamps and can be installed on the rooms ward or in a distributor and connects to the overriding central unit (via corridor data bus). Used as a call interface to inform about incoming technical alarms from a 3rd party system, this is particularly suitable for warning indications that must be notified to all caregivers. It is possible to use the 4 inputs of the I/O Interface to receive up to 4 external technical alarms, which will be displayed throughout the system. Each input can be configured with a separate text for identification. The configuration data of the device and associated profiles (functions, identification texts, I/O operation mode, ...) are stored locally (flash memory). Includes a backward compatibility mode for usage as replacement of legacy Contact Interface 99, for existing systems in accordance with DIN VDE 0834-1: 2016-06. Integrated switch to configure the operation mode of inputs as normally closed (NCC) or normally open (NOC). Upgradable to future system firmware thanks to advanced flash storage technologies. Includes the option for automated software update during operation. 72593D