ABSTRACT
The costs for system-commensurate electromagnetic compatibility planning and implementation are much less than the costs, tangible and intangible, of an unhardened system, causing downtime, destruction, accidents, and lawsuits. Manufacturers of unsafe systems will lose their reputations and their businesses will suffer. The EDP equipment, centralized and/or partly localized (in the form of microprocessors), arrives at decisions about what to do and sends control information via 0/1 devices, being part of the control channels, to corresponding receptors and triggering devices. Now, although sensor and control links are designed as communication systems, they are tightly immersed in the noisy machine environment. This noise includes ubiquitous 60 Hz fields and currents. In this hostile environment, weak sensor signals must be enhanced by pre-amplifiers which may pick up strong interference via ground loops, mode conversion, power supplies, and so on. In ground systems, low-frequency and high-frequency effects are very different.
