dSPACE DS1103, Hardware Installation And Configuration Manual

Page: 199 / 302

EMC radiation and immunity are mostly affected by the outer cable
shield. Individual lead shielding has only a minor effect if a common
outer shield is present. Individual shielding is only necessary to reduce
crosstalk.
For cabling you should use shielded, twisted pair cables. The inner
twisted
‑
pair leads are used for the signal line and the return line
(ground line). The return line should be connected to the ground pins
of the respective board connector.
Ideally, each signal should be twisted with its return line so that any
electromagnetic fields cancel one another.
Using the encoder interface with differential signals, the PHI90 line
should be twisted with PHI90, PHI0 with PHI0 et cetera.
Cabling
Use a metal shell connector to the dSPACE board connector and
connect the shield to the connector shell so that shield, connector
shell and system enclosure form a closed shield surrounding all
electronics. Use a large area connection and avoid pigtails.
Do not connect the shield to the GND pins of the
dSPACE system.
Connecting shield to the
dSPACE system
At the other end, the shield should be connected directly to the
sensor/actuator housing. Sometimes sensors and actuators have
dedicated shield pins available at their connector. The idea is to form
one closed shielding cage consisting of the cable shield and
sensor/actuator enclosure, which is ideally nowhere connected to
signal ground. Use a large area connection and avoid pigtails.
Connecting shield to the
external device
s
Grounding and Shielding
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DS1103 Hardware Installation and Configuration November 2014 199
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