I/O Terminal /
MOUNTING AND WIRING
15
The right hand part of the Bus Coupler can be compared to a Bus Terminal. Eight connections at
the top enable the connection with solid or fine wires from 0.08 mm² to 2.5 mm². The connection
is implemented with the aid of a spring device. The spring-loaded terminal is opened with a
screwdriver or rod, by exerting gentle pressure in the opening above the terminal. The wire can
be inserted into the terminal without any force. The terminal closes automatically when the
pressure is released, holding the wire securely and permanently.
3.3 Wiring
The section provides potential groups, insulation testing, and PE information for the
PROFIBUS Coupler.
3.3.1 Potential
Groups
The Bus Terminals stations usually have three different potential groups:
The fieldbus interface is electrically isolated (except for individual Low Cost couplers) and
forms the first potential group
Bus Coupler / Bus Terminal Controller logic, Standard-Bus and terminal logic form a
second galvanically separated potential group
The inputs and outputs are supplied via the power contacts and form further potential
groups.
Groups of I/O terminals can be consolidated to further potential groups via potential supply
terminals or separation terminals.
