7.2 List of Abbreviations

  • LN – 2N® LiftNet
  • CU – Central unit of the system, typically shared by multiple lifts in a building
  • Audio Unit – Voice communication unit for lift communication with the dispatching office or another system unit
  • System – Central unit interconnected with a group of audio units by a bus
  • Bus – A pair of conductors interconnecting the CU and all system audio units
  • Incoming call – dispatching office-to-CU call
  • Outgoing call – CU-to-dispatching office call
  • Checking call – Automatically activated CU-to-dispatching office call
  • Triphony – Internal communication between audio units, typically all audio units of one and the same lift, during repairs or rescue work
  • Dispatching office – Receives emergency calls, checking calls and, if necessary, lift failure reports. Separate dispatching offices can be responsible for different types of calls and mobile telephones can be used too.
  • LM, LiftManager – Supervisory software designed for small and medium-size lift supervising companies. Automatic receiving of checking calls. Comfortable programming of CU parameters.
  • DISA – Automatic voice menu, which helps route incoming calls to the required audio unit or activate additional functions, e.g. remote programming
  • ESS – Electronic Security System
  • PBX – Private branch exchange (equipped with PSTN interface and local analogue lines)
  • PSTN – Public switched telephone network. For simplification, it is assumed that the CU is connected to the PSTN although it works on the PBX line too in the same way