Quick Start Guide REX 200/250 3G | LTE
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2.3.2 Internet access options
In the case of these device variants, a GSM mobile connection can also be configured
as an alternative to the P1 WAN interface, which establishes the Internet connection
via a higher level network/router. In order to be able to log into the GSM network, at
least one mini SIM card of a provider of your choice must be inserted into the SIM 1
slot. The SIM card holders are found on the left side of the housing. To remove, press
the unlocking button next to the insert
2.3.3 Antennas
The required GSM antennas with SMA plugs are available in Helmholz accessories.
The installation location must be selected such that adequate GSM reception is pos-
sible. Due to the shielding effect, antennas should not be installed in metal housings
(e.g. In the control cabinet). When using antenna extensions, the instructions from
the technical data sheets of the manufacturers are to be observed.
2.3.4 REX 200/250 3G (UMTS)
The antenna required for radio reception is screwed onto the SMA socket “ANT”.
2.3.5 REX 200/250 LTE (4G)
For radio reception, a suitable antenna must at least be screwed onto the SMA socket
“MAIN”.
In order to improve the data throughput, a second antenna terminal is available on
the REX 200/250 LTE router with the SMA socket “Rx” that can be used as an option.
This functionality is called antenna diversity in the “WCDMA mode” and Downlink-
MIMO in the “LTE mode”.
The second receiver antenna should not be located in the immediate vicinity of the
main antenna. In order to improve the diversity gain and reduce other reciprocal
interactions (interference effects), the two antennas should be (taking the space
available in the application into account) installed with the greatest possible distance
between them.
For the same reason, the second antenna should be mounted cross-polarized
(rotated by 90° in relation to the main antenna).
