Users Manual

WAL - Work Area Limitation Module Connections and wiring
5 Connections and wiring
5.1 EMC and wiring guidelines
5.1.1 Personal safety and exposure
Safety extra-low voltage
The module is powered by safety extra-low voltage.
Radiated power
The EIRP value of the WAL R1 module is -1.21 dBm at maximum and
therefore far below the applicable limit.
5.1.2 Why EMC-aware wiring?
The immunity of an electrical system depends essentially on wiring and
shielding that is designed to overcome any EMC problems. Servicing
experience has shown that inadequate wiring and shielding is a common
cause of system interference and failure.
Electromagnetic interference is far more troublesome than "conventional"
faults:
⚫ It is not normally recognised as such from the symptoms displayed and
can often be mistaken for a fault in an assembly, which is basically
sound.
⚫ They mainly occur sporadically and are difficult to duplicate.
As a consequence fault-finding is time-consuming and expensive.
Therefore ensure from the start that the wiring and shielding
conforms to the guidelines documented below.
5.1.3 Which EMC measures must be taken?
The EMC measures for the WAL module concentrate on shielding the
connecting cable of the module.
5.2 Power supply
The power to the WAL R1 module is supplied via the connectors for
communication (3.3V or 5V).
The high-frequency area (U2, U10: AT86RF215) generates the voltages it
uses by itself.