Insys Modem 56k 4.1 11-02-01-01-40.028 Manuale Utente

Functions 

INSYS Modem 336/56k 4.1 (UL) 

If a telephone connected in series goes off-hook during an 
existing modem connection, the modem will immediately 
terminate the connection. 
The telephone is connected to the line and receives a dialing 
tone. 
In the registry S86, the value is set to 25. 
When the phone connection is terminated, the modem will 
not establish a new connection. 
 

Changing the loop voltage to detect the function – Off-hook 
on account of a telephone connected in series (U2) – can be 
set with the help of AT commands. 

 

 

 U2, U3 

Loop voltage prior to 
start of connection.

 

Loop voltage after a 
phone in series is 
picked up. 

The detection starts immediately after the 
handset is picked up. To access the exchange, 
simple analogue phone systems often connect 
the modem per contact directly with the ex-
change, which results in a strong change or po-
larity reversal of the loop voltage.  For some 
analogue phone systems, this may result in an 
erroneous detection. Off-hook detection is 
therefore not recommended in connection with 
analogue phone systems. 

40

 

 

July 06