Incoming call – A call from the dispatching centre to the central unit
Outgoing call – A call from the central unit to the dispaching centre
Checking call – An automatically activated call from the central unit to the dispatching centre
Dispatching centre – A workplace that receives emergency calls, checking calls, and lift error reports if any. There may be separate workplaces, each for one type of calls, even mobile ones
L8, 2N® Lift8 system , The software part can handle checking calls, alarm calls, DB of all intercoms.
PBX – A private branch exchange (equipped with a PSTN line and local analog lines)
PSTN – The public switched telephone network. It is assumed for simplification that ST is connected to the PSTN although it works on a PBX line in the same way
