Advantech RS-485 user manual Noise Reduction Techniques

Grounding Reference

•Shield connection (2)

Above diagram shows you that the fill soldering just makes a easier way for the signal.

F.3 Noise Reduction Techniques

•Enclose noise sources in shield 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.

•It’s almost communication problem while system unstable.

•Add another Grounding Bar if necessary.

•The diameter of power apply cable must be over 2.0 mm2.

•Independent grounding is needed for A/I, A/O, and communication network while using the jumper box.

•Use noise reduction filters if necessary. (TVS, etc)

•You can also refer to FIPS 94 Standard. FIPS 94 recommends that the computer system should be placed closer to its power source to eliminate load-induced common mode noise.

F-14 ADAM-5000