User Guide

PAMS
Technical Documentation
NME–3
Technical Information
Page 17
Issue 1 10/99
Figure 5. Digital interface in GM8B
MAD
F–Bus Rx
F–Bus Tx
M–Bus
RS232
Level
shifter
Data
connector
System
connector
Handset
Flash/Test
equipment
&
Row 0..4
Col 0..4
SYS Conn Block Conections
Audio Block Connections
The Cobba has to functions AD/DA converters for the RF–BB interface.
Codecs for the Audio interface. The RF–BB interface is used implemented
in the same way it is implemented in HD940. The Cobba audio interface is
used different to the handys. The Inputs and outputs for HS–use, which
are normally connected directlly to the Microphone and the earpiece are
connected to the Handset via balanced drivers and receivers. The
Handsfree input and output is connected to the analog HFanalog audio
parts on the RU PCB via Balanced lines as well.
Audio Connection to Handset
The audio interface to the HS will not be reused from CD 940. It consists
of balanced audiolines from Cobba to Earpiece and from HS Microphone
to Cobba.