SOS switch, function - GF82.95-P-4107-04TM

In the quiescent state an electric current flows via the control resistor (parallel to switch contact) that is built into the SOS switch (S93/3s1). The emergency call system control unit (N123/4) uses this to detect whether the feed line and the ground line are OK. When the SOS pushbutton switch (S93/3) is pressed the control resistor is bridged by the switch contact.

The SOS switch (S93/3s1) signal is read in via a discrete line by the emergency call system control unit (N123/4). When the SOS switch (S93/3s1) is operated the emergency call system control unit (N123/4) detects a manual emergency call and then places the call.