A few people have inquired about documentation on noise abatement techniques. There really isn't any formal document since it is difficult to make it all encompassing. Here are a few techniques that are considered "first to try" when confronted with noise in a system.
1) Use good quality ethernet cables. Cat 5e and Cat 6 would both be good choices especially for the ECOM100's. Even thought they are more expensive, the higher quality cables will do better in terms of keeping the noise from getting into the system. It's worth the extra cost.
2) Try to keep the ethernet cables away from cables that carry power to loads. The noise generated by switching heavy loads can enter into the module via the cable. For example, adopt a strategy such as routing signal cables on the bottom side of the system and noisier load related cables on the top side. Also, use separate trays for signal cables and load related cables.
3) Relay modules that switch high voltage loads positioned next to the ECOM's can cause problems. When designing a system, consider placing the ECOM near the CPU (but not in slot 0) and relay modules at the far end of the base.
4) The power for the base can also be a source of conducted noise. Try to keep the power cable away from load related cables.
The noise will be additive so efforts in all areas will result in a more robust system. The more the noise can be reduced, the lower the probability of failure.
In any system, understanding the layout and grounding strategy is important in developing a robust system. Sometimes a schematic of the system will help in the identification of areas that are weak. Attention to detail is important. Some of the simplest things can provide the greatest improvements.
Topic: Reducing noise related issues in ECOM100's (Read 3638 times)