B.4 Noise Reduction Techniques
Isolate noise sources in shielded enclosures.
Place sensitive equipment in shielded enclosure and away from computer equipment.
Use separate grounds between noise sources and signals.
Keep ground/signal leads as short as possible.
Use Twisted and Shielded signal leads.
Ground shields on one end ONLY while the reference grounds are not the same.
Check for stability in communication lines.
Add another Grounding Bar if necessary.
The diameter of power cable must be over 2.0 mm2.
Independent grounding is needed for A/I, A/O, and communication network while using a jumper box.
Use noise reduction filters if necessary. (TVS, etc)
You can also refer to FIPS 94 Standard. FIPS 94 recommends that the com- puter system should be placed closer to its power source to eliminate load- induced common mode noise.
Figure B.15 Noise Reduction Techniques
B.5 Check Point List
Follow the single point grounding rule?
Normal mode and common mode voltage?
Separate the DC and AC ground?
Reject the noise factor?
The shield is connected correctly?
Wire size is correct?
Soldered connections are good?
The terminal screw are tight?
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