Aastra MX-ONE Installation Instructions Manual page 126

Installing MX-ONE
6.4.2 ISDN Extensions with ELU26
The ISDN-terminals are connected to the ELU26 board in the PBX through
the MDF.
Figure 92
6.4.3 Door Signal
A door signal (call in progress) can be connected to the system telephone.
The digital system telephone contains an output circuit (opto-switch) that has a
maximum driving capacity of 15 V, 2 mA.
The use of the door signal function requires the connection of a buffer amplifier
and an external power source.
The buffer amplifier and the power supply equipment are to be procured locally.
120
Example with an ISDN-terminal, 4-wire connection
6/1531-ASP 113 01 Uen J2 2008-07-17