
Appendix
S7-300 Programmable Controller Hardware and Installation
A5E00105492-01
11-5
Table 11-5
Coupling mechanisms
Coupling
mechanisms
Cause
Typical interference sources
Galvanic
coupling
Galvanic or mechanical
coupling always occurs when
two circuits use one common
cable.
•
Clocked devices (influence on the
network due to converters and
third-party power supply modules)
•
Starting
motors
•
Potential differences on component
enclosures with common power
supply
•
Static
discharge
Capacitive
coupling
Capacitive or electrical
coupling occurs between
conductors connected to
different potentials.
The coupling effect is
proportional to voltage
change over time.
•
Interference coupling due to
parallel routing of signal cables
•
Static discharge of the operator
•
Contactors
Inductive
coupling
Inductive or magnetic
coupling occurs between two
current circuit loops. Current
flow in magnetic fields
induces interference voltages.
The coupling effect is
proportional to current change
over time.
•
Transformers, motors, arc welding
devices
•
Power supply cables routed in
parallelism
•
Switched cable current
•
High-frequency signal cable
•
Coils without suppression circuit
Radio frequency
coupling
Radio frequency coupling
occurs when an
electromagnetic wave
reaches a conductor system.
This wave coupling induces
currents and voltages.
•
Neighboring transmitters (e.g. radio
phones)
•
Sparking (sparkplugs, collectors of
electrical motors, welding devices)
Summary of Contents for Simatic S7-300
Page 10: ...Contents S7 300 Programmable Controller Hardware and Installation x A5E00105492 01 ...
Page 16: ...Preface S7 300 Programmable Controller Hardware and Installation 1 6 A5E00105492 01 ...
Page 22: ...Quick Guide S7 300 Programmable Controller Hardware and Installation 2 6 A5E00105492 01 ...
Page 28: ...Product overview S7 300 Programmable Controller Hardware and Installation 3 6 A5E00105492 01 ...
Page 74: ...Configuring S7 300 Programmable Controller Hardware and Installation 4 46 A5E00105492 01 ...
Page 102: ...Wiring S7 300 Programmable Controller Hardware and Installation 6 18 A5E00105492 01 ...
Page 148: ...Commissioning S7 300 Programmable Controller Hardware and Installation 8 36 A5E00105492 01 ...
Page 236: ...Glossary S7 300 Programmable Controller Hardware and Installation 12 16 A5E00105492 01 ...