3 checking the use of repeaters, Checking the use of repeaters, 5installation – Lenze EMF2180IB User Manual
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Lenze · EMF2180IB communication module (EthernetCAN) · Communication Manual · DMS 5.0 EN · 07/2014 · TD17
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5
Installation
5.2
Electrical installation
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5.2.3.3
Checking the use of repeaters
Compare the values derived from tables
and
• If the sum of the segment cable lengths is smaller than the total cable length to be
implemented, either repeaters must be used or the cable cross-section must be increased.
• If the use of repeaters reduces the max. possible total cable length so much that it is smaller
than the total cable length to be implemented, then the cable cross-section must be increased
or less repeaters must be used or the baud rate must be decreased.
• The use of a further repeater is recommended as ...
• service interface
Advantage: trouble-free connection during bus operation is possible.
• calibration interface
Advantage: the calibration/programming unit remains electrically isolated.
Example
Given
Total cable length to be
implemented
450 m
Number of nodes
32
Cable cross-section
0.50 mm
2
(AWG 20)
Baud rate
125 kbit/s
Repeater used
Lenze repeater EMF2176IB
Reduction of the max. total cable
length per repeater (EMF2176IB)
30 m
Results
Max. possible total cable length
600 m
(see table
)
Max. segment cable length
360 m
(see table
)
Comparison
The max. segment cable length is smaller than the total cable length to be
implemented.
Conclusion
A repeater must be installed at the determined max. segment cable length
of 360 m.
Results with 1 repeater
Max. possible total cable length
570 m
(Reduction of the
by 30 m)
Sum of the segment cable lengths
720 m
Comparison
Both the possible total cable length and the segment cable lengths are larger
than the total cable length to be implemented.
Conclusion
1 repeater is sufficient to implement the total cable length of 450 m.