Omron 3G3RX User Manual page 52

2-2 Wiring
2
Controller signal shields connect only to the ends: Single end or both but never midway.
Control signals are not emitter, therefore the target is to create a coverage acting as antenna for the
radiated emissions and drain them through single point to the ground... multiple shielding points at
different potentials will create undesirable recirculating noise currents through ground loops.
Ensure controller signals shield continuity: Control lines should remain without interruptions
directly connecting signal source and signal reception. Should the case this is not possible (terminal
box, plug connector or contactor / relay absolutely needed) then this elements should be selected
of the highest quality and adequate for the signal to be managed (it is not the same a START/STOP
24VDC signal, than a 5VDC TTL encoder signal, than a 1Vpp sinusoidal signal of a SINCOS
technology encoder from lower to highest sensivity to connection quality). As well, shield should be
guaranteed continuity by passthrough contact, and never become grounded in this interruption
point. We recommend high quality connectors that handle the shielding.
Encoders and sensors from the field: In this case follow the recommendations of the manufac-
turer of the sensor device. Most encoders and sensors with shielded cables will recommend 360º
wrapping of the shield both at the sensing end and at the inverter end. For many of them, the shield-
ing and grounding will be integral to the body of the sensor.
2-27
twisted pairs (differential signals)
control signal shield passthrough