FNM alpha SM 230, User Manual, Page: 20 / 72

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Description of device-specific features
Analogue In
The analogue inputs are for measuring analogue voltages (e. g. level transmitter).
There is a total of three analogue inputs available, two of them can be operated in the
range 0 - 2.5 V and one can be operated in the range 0 - 10 V. The analogue inputs
refer to AGND.
Analogue Out
The analogue outputs are for the activation of actuators with analogue interface. They
can be operated in the range 0 - 2.5 V and refer to AGND. Two analogue outputs are
available.
Digital In
The digital inputs are for measuring digital signals (e. g. limit switch, state signals). Two
digital inputs are available.
Digital Out
The digital outputs are for the switching of actuators or for the status output. Two digital
outputs are available.
Repeater module
The repeater module has the function to transfer the data within the network. In case
a sensor module is too far away from a base module to reach it directly, the range can
be raised by using a repeater. Thereby, it is possible to set up spatially long-range net-
works by means of sensor modules with low transmitting power. This raises the energy
efficiency and therewith considerably raises the lifetime of the battery.
The repeater modules have to send more often than sensor modules and have to be
ready to receive all the time since they possibly transmit packets of data of several
sensor modules. They are as a rule firmly installed at topological favourable points and
are fed by a power supply unit. In case of need, battery operation is also possible over
a short period of time.
The repeater module RM 300-G is available in an IP65 housing, the repeater module
RM 300 is available as PCB version.
When setting up the network, you have to mind that the number of repeaters in the
network is kept low in order not to stress the network excessively by manifold packet
forwarding.
Repeaters should also be installed in places with good radio propagation conditions
(e. g. isolated, elevated mounting places). This raises the range and the quality of the
whole network.