Elgas DATCOM, Operating Instructions Manual

Page: 133 / 228

7
Technical Description of the Device
131
7.7 Internal Modem, Using External Antenna
The internal M2G, M4G modem is powered by a stand-alone HB-03/HB-03D battery. The modem
is fully controlled by the device parameters. Due to the current consumption of the modem, it is
necessary to choose the mode and timing of the transmitted data and to control the switching ON
and OFF of the modem with respect to the modem battery. For the ELCORplus and ELCORplus
Indexer, the internal modem can also be powered from an external power supply (PS-M, PS-M/A)
using the S4-PWR2 module.
7.7.1 Using the Device with an External Antenna
The internal M2G and M4G modems are equipped with an integrated antenna that is part of the
M2G or M4G modem. The antenna is located under the modem module cover and is connected
to the modem board via a standard SMA connector.
In locations with poor signal quality, the internal antenna can be disconnected and an external,
more powerful antenna, attached to the coaxial cable outside the device, can be connected. This
modification is based on the installation of a HF cable adapter that interconnects modem antenna
outlet with outer antenna plug. The required part - HF cable adapter - see Fig. 64 must be
ordered separately, it is not included in the standard delivery.
An external antenna (not included in the standard accessory) is connected to the SMA (f) panel
connector at the bottom of the device enclosure.
The external antenna may be located in a potentially explosive zone or in a safe environment.
WARNING:
When designing the installation and use of an antenna other than the supplied standard one,
especially when located outside a potentially explosive zone, measures must be taken to reduce
the impact of the lightning strike (see CSN EN 60079-14 and CSN EN 62305 3).
The maximum cable length for the external antenna is 10 m.
7.7.2 Modifying the Device for Connecting an External Antenna to the
Modem
Procedure:
 If external power supply of the modem is
used, first disconnect power source from
PWR2 terminals.
 Press mechanical lock of the connector on
the modem battery cable and pull the cables
gently to disconnect the modem battery.
 Put SIM card cover (1) to the vertical
position, open it slightly, and remove the
modem plastic cover.

Hold the fixed part of the connector (2) with a
flat key size 7 to prevent the part from
slipping out of the printed circuit board, and
release the nut of the inner antenna connector (3) nut with a key size 8.