2N Lift emergency phone 2N SingleTalk - Manual, 1514 v6.3.0 - Manual (Page 59)

Function Description 4.1
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4.1 Function Description
Note
 The information in this section is intended for those who are familiar with the
foundations of telecommunications equipment and need to know detailed
processes taking place in ST. It is unnecessary for common ST installations.
Outgoing Call
The ST is activated by pressing the ALARM button. After that, the ST “seizes“ the line
and establishes connection with the hotline or dispatching center personnel (for details
see Automatic Dialing). During the call establishing, the person in the lift hears the
dialing tone, then the DTMF dialing tones and the ringing tone, or “Wait please,
connection is being made“, or any other suitable message. The message usually starts
with the "Wait please, connection is being made“ statement and may include the ST
identification (address, lift number, etc.). Once the dispatching service answers the
phone, the parties can start talking with each other
Checking Call
The Checking Call is an automatic outgoing call whose purpose is to check the ST
function. If activated, the function runs every 72 hours (3 days). The procedure is
similar to that of an outgoing call. The difference lies in that a different message is
played back, e.g. “Checking call“, and a different set of numbers may be used.
Checking calls are typically received automatically – in case the dispatcher‘s centre is
equipped with the 2N
® LiftManager software. A standard PC with an analog modem
can be used for running the program.
Incoming Call
The dispatching center can also call the ST number. The ST answers the call after two
rings (the count of rings is parameter-defined) and sends a sound signal. Now, for
example, the person trapped in the lift keeps informed about rescue operations. Also,
it can be checked remotely whether the ST has been connected and works.
Protection against Unintentional Initiation
Since the main purpose of the ST is to call help in case of emergency (whenever a
person gets trapped in the lift), any call can be regarded as unnecessary, if the lift
cabin door is open. So, where available, a door contact can be connected to the ST
input labeled as CANCEL and a delay can be programmed for the ST to make
connection after the ALARM button is pressed. Therefore, in case someone presses the
ALARM button by mistake, the lift gets to a certain floor during this delay, the door
opens and the call is cancelled. Or, it is possible to set the minimum button pressing
time to avoid most false ALARM cases.