Videx GSM4K/4G - USB & RS485 Connection to a PC; CONNECTIONS TO A PC; OPTION 1: USB CONNECTION; OPTION 2: RS485 CONNECTION

66250754-4G-EN - V2.0 - 28/03/22
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4000 Series GSM Audio Intercom - Technical Manual
4000 Series GSM Audio Intercom with Proximity
USB & RS485 Connection to a PC
CONNECTIONS TO A PC
The 4G GSM module includes three options for connecting to a PC: via a USB connection or via an RS485 connection. All methods
of connection are to allow for ease of programming and monitoring using the GSMSK PC software.
IMPORTANT: WHEN A USB CONNECTION IS PLUGGED INTO THE 4G GSM THE RS485 CONNECTION IS DISABLED.
All programming features described in this manual are also accessible using the software. Further information on using the GSMSK
PC software can be found in the technical manual GSMSK_66251720-EN_V2-1 (or later version).
OPTION 1: USB CONNECTION
The GSM module can be connected using a standard micro-USB to USB cable as shown in Fig.34. This method of connection is
primarily used for programming and setup of the GSM module only.
To Antenna
Art.4810/4G
micro-USB to USB cable
IMPORTANT NOTE:
The USB input is not intended for a
permanent connection to the PC and
should only be used for programming.
For a permanent connection refer to
OPTION 2, RS485 notes below.
Fig. 34
OPTION 2: RS485 CONNECTION
The GSM module can also be connected using an RS485 bus connection via an RS485 to USB converter (Art.481) as shown in
Fig.35. This method of connection, like option 1, can be used for programming and setup of the GSM module, 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 GSM module 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.
Art.4810/4G
To Antenna
RS485 cable
485 / 232
RS-485
USB-PC
A B GND
RS-232
Art. 481
USB-Serial Converter
Open
Close
BUS
Termination
USB cable
switch to RS485 position
BUS
termination
jumper in
the closed
position
PC
Fig. 35
*For end of line termination a 120Ω resistor must be tted across the RS485 terminals A and B, as shown in Fig.35, but only if the
4G GSM intercom is the last device in line and over a great distance (up to 500m max.). Over shorter distances (less than 100m) the
120Ω resistor is not required and the bus termination jumper on the Art.481 can be set to the OPEN position.