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The write-protect function ensures that all the
required information can be transmitted, but
prevents any changes to the status of the circuit
breaker. Changes can then only be made locally.
Why does the write protection function permit
certain actions?
All actions that are not blocked are for remote
analysis only and do not have any effect on the
current status.
Data Exchange via the COM15 Module
When the COM15 module is configured to
exchange data, it is important to note that it
is shipped as standard with PROFIBUS address
126. This can be changed during system
configuration (e.g. with the BDA or ETU776
display).
The COM15 module has two LEDs (PROFIBUS
and CubicleBUS) for diagnostic purposes.
These indicate the operating status of the
communication line and the CubicleBUS networks.
Two LEDs are used to determine whether a
CubicleBUS module in the circuit breaker is
operational. First, the "COMM" LED on the trip
unit must be green, that is, the trip unit has
recognized at least one other CubicleBUS module.
At a minimum, this would only be the Metering
Function/Metering Function PLUS if the CubicleBUS
was then interrupted. Second, the CubicleBUS
LED on the COM15 module must be taken into
account. If this is lit with a steady green light, a
connection exists from the COM15 module to at
least the metering function/metering function
Plus module.
If both LEDs are green (steady light for CubicleBUS
on the COM15 module and COMM on the trip
unit), communication is fully established between
the trip unit and the COM15 module.
Data is exchanged according to the following
principle: an up-to-date copy of all WL Circuit
Breaker data (apart from the waveform buffer) is
always stored in the COM15 module. A response
to a data query from the COM15 module to the
supervisory system can, be typically transmitted
in just a few milliseconds. Write data from the
supervisory system is forwarded to the
appropriate addressee on the CubicleBUS.
WL PROFIBUS Communication and Electronic Accessories • July 2004
Communication-capable Circuit Breakers
Front view of the PROFIBUS module for the WL Circuit Breaker with the
Figure
PROFIBUS connection and the two LEDs. The figure below shows a section
2-1
of the ETU745 and its LEDs for displaying status.
Rear view of the COM15 module. The RJ45 connection for the external
Graphic
CubicleBUS modules can be clearly seen here. If no external CubicleBUS module
2-2
is connected, the bus must be terminated with the terminating resistor.
Meaning
CubicleBUS -
CubicleBUS +
24V DC +
24V DC ground
Table 2-3
The 4 black cables from the COM15 module must be connected to
terminal strip X7, which is used to connect the COM15 module to the modules on
the CubicleBUS in the circuit breaker.
WL Circuit Breaker
Position and text on the cable
X7.1
X7.2
X7.3
X7.4
2/10
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