66251750-EN - V1.0 - 05/06/17
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4000 Series Digital GSM - Technical Manual
4000 Series Digital GSM Audio Intercom with Proximity
OPTION 2: RS485 CONNECTION
The digital GSM intercom can also be connected using an RS485 bus connection via an RS485 to USB converter (Art.481) as shown
in
Fig.15
. This method of connection, like option 1, can be used for programming and setup of the digital GSM, but can also be
used in instances where a permanent connection to a PC is required for monitoring purposes and downloading event logs. When
connected in this way the digital GSM can only be connected as a ‘one-to-one’ bus connection to the PC, another GSM module
cannot
be connected on the same RS485 bus to the PC.
%0
A
B
GND
12V
0V
PTE
AI
TRD
AO
NC
CO
NO
USB
4812
4812R
RS485
Vandal Resistant 4000 Series Digital GSM Panel
485 / 232
RS-485
USB-PC
A
B GND
RS-232
Art. 481
USB-Serial Converter
Open
Close
BUS
Termination
PC
USB cable
RS485 cable
switch to RS485 position
BUS termination
jumper in the
closed position
Fig. 15
*For end of line termination a 120 Ohm resistor must be fitted across the RS485 terminals A and B, as shown in
Fig.15
.
USB & RS485 Connection