LW21501d_e.doc / Feb-13 Page 6 / 9
2.2. Electrical Connections
As a principle, the input and output lines always must be routed pairwise, i.e. both wires of a
differential signal must be routed in a twisted pair of cables. The use of bundle wires (called
control cables) is not allowed, since this will not guarantee correct signal transmission nor EMC
compliance.
The cable shield must be connected at both ends, at the encoder and the optical fiber
transmitter, and at the optical fiber receiver and the signal processing device. The optical fiber
transmitter and receiver are equipped with the additional ground pin 11 for this purpose.
For the modules with RS-422 output (LW214/LW214-1/LW216 and LW216-1),
please make sure that the signal receiver provides a differential input with an
input resistance of 100 – 120 ohms.
For modules LW214-2 and LW216-2, this value must be 2 kohms.
If there are no specific requirements for the output signals of the receiver modules (e.g. low
transmission frequencies in the lower kHz range), the outputs may be operated as single-pole
TTL or HTL outputs. However, the correct operation of this application must be checked on a
case-by-case basis, and it is not supported by the manufacturer.
All modules are protected against reversed polarity, in order to avoid damage in case of wrong
polarity of the power supply.
The outputs of the modules are only conditionally short-circuit proof; therefore please avoid
imperatively short-circuits between modules or with the earth.
Exceeding the supply voltage of the modules LW213, LW214, LW215 and LW216 above a value
of about 6 V provokes destruction of the fuse located inside of the device and must thus be
avoided.
For the modules LW213-1, LW213-2, LW213-3, LW215-1, LW215-2, LW215-3, LW214-1,
LW214-2, LW216-1 and LW216-2, this value is 33 V.
The fuse can only be replaced in the manufacturer’s factory. Any attempt to
repair the device will void the warranty.
