10.2 List of Abbreviations

L8	2N^® Lift8
CU	System central unit, typically shared by multiple lifts in one building.
Splitter	Interconnects audio units and the CU. Each lift shaft has a splitter of its own.
Audio unit	Audio unit used for voice communication with the control centre or another system unit.
System	CU connected with a splitter and group of audio unit.
Main bus	6 wires (power, audio, data) connecting the CU with splitters.
Bus	Double wire connecting the splitter with lift audio unit.
Incoming call	Call from the control centre to the CU.
Outgoing call	Call from the CU to the control centre.
Check call	Call from the CU to the check call line registered in 2N^® Server or another number defined.
Triphony	Inter-audio unit communication, typically between all audio units of one lift, during repairs or rescue operations, for example.
Control centre	Workplace receiving alarm calls. There can also be separate workplaces for various call types or just the staff mobile telephones.
DISA	Automatic voice menu for incoming call routing to the required audio unit or function activation, remote programming, e.g.
PBX	Private branch exchange (equipped with PSTN connection and analogue local lines).
PSTN	Public telephone network. For simplicity, it is assumed that the CU is connected to the PSTN but works identically on the PBX line too.
GSM	Global System for Mobile Communications
UMTS	Universal Mobile Telecommunications System
TCP	Transmission Control Protocol is one of the set of Internet protocols.
ST	The 2N^® Service Tool application is intended for remote supervision and configuration of 2N^® Lift8 communicators.
CP	The 2N^® Control Panel application is intended for the administration of users, lifts and authorisations.
CM (Comm)	The 2N^® Communicator application is intended for receiving alarm calls by the dispatcher.
SRV	The 2N^® Server application processes check calls and mediates communication between the CUs and PC applications.
Validator	This code monitors the values entered in the applications, and in the event of an error such as excessive length, forbidden character, incorrect format etc., warns the user.