Glossary - Siemens Simatic MP 377 Operating Instructions Manual

Glossary

Degree of protection
The degree of protection specifies a standard of electronic equipment for a variety of
environmental conditions – and the protection of persons against potential danger when
using this equipment.
The degree of protection specified by IP differs from the protection class. But both involve
protection against touching dangerous electric voltage. The degree of protection also
classifies the protection of equipment against dirt and moisture.
Electromagnetic compatibility
Electromagnetic compatibility (EMC) refers to a usually desirable state, in which technical
equipment does not disturb one another with unwanted electrical or electromagnetic effects.
Electromagnetic compatibility deals with technical and regulatory questions of undesired,
mutual influence in electrical engineering.
PLC
A PLC influences the workflow of a plant or a process according to a specified plan. The
output variables are set depending on the input variables and the status variables. An HMI
device usually monitors these variables and communicates with the PLC.
Protection class
The protection class is used in electrical engineering to classify and identify electrical
equipment in relation to existing safety measures designed to prevent electric shock.
There are four protection classes for electrical equipment.
MP 377 15" Touch daylight readable (WinCC flexible)
Operating Instructions (Compact), 04/2009, A5E02532357-01
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