Rockwell Automation System Design for the Control of Electrical Noise - Manual (Page 88)

Publication GMC-RM001A-EN-P — July 2001
10-2 Encoders
Wiring
• Always use shielded cable (manufacturers usually specify
appropriate cable).
• Segregate the cable as far as practical from dirty and especially
very-dirty wiring.
Power
• Always use the internal power supply when available.
• Ensure the power supply has a clean rating (refer to Figure 10.1
and Figure 10.2 for linear and switch-mode power supply
examples).
• Use a filter if a switch-mode supply is used (refer to the chapter
Filtering Noise for more information).
• Always ground the common.
Mounting
• Insulate the encoder body from the machine structure and connect
it to the cable shield.
Note: This strategy also requires an insulated shaft coupling.
• If the encoder cannot be insulated, connect the cable shield to
ground at the encoder case and drive chassis (or dedicated
termination).