dSPACE DS1103, Hardware Installation And Configuration Manual

Page: 198 / 302

On the sensor/actuator side, connect one of the twisted wires to the
signal and the other one to ground. On the board side, connect the
first wire to the input/output and the second one to ground. The
shield should be connected to the housing of the sensor/actuator and
to the metal shell of the board connector. Do not connect the shield
to ground anywhere.
Signal return line A
Signal A
Shield
Signal B
Metal shell
Shielded twisted pair cable
I/O pin
GND pin
I/O connector
If not enough ground pins are available at the connector, several
return lines can be attached to a common ground pin. However, this
common ground lead should be kept as short as possible to reduce
ground line inductance.
If a cable contains unused leads, connect them to signal return
(ground) lines at both ends to lower the inductance of the ground
path between the dSPACE system and the sensor/actuator.
In a star ground configuration, ground loops are of no concern, if the
signal return (ground) lines within the external devices are not
connected to protective ground.
Always connect all signal return (ground) lines at both ends of a
cable, i.e. board connector and sensor/actuator.
Star ground configuration
Shielding
The best shield is a low
‑
inductance conductive barrier surrounding the
complete setup of the device, cable and system, keeping in everything
inside and keeping out everything outside (faraday cage). Low
resistance, and most especially low inductance, are the key to a good
shield.
General
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General Notes and Tips on Signal Conditioning
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198
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DS1103 Hardware Installation and Configuration November 2014