Checking the use of repeaters
Compare the values derived from Tab. 1 Total cable length (^ 53) and Tab. 2 Segment cable
length (^ 54).
ƒ 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.
ƒ 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.
ƒ 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
Number of nodes
Cable cross−section
Baud rate
Repeater used
Reduction of the max. total cable
length per repeater (EMF2176IB)
Results
Max. total cable length
Max. segment cable length
Comparison
Conclusion
EDKMF2180 DE/EN/FR/ES/IT 4.0
Electrical installation
Connection of system bus (CAN)
450 m
32
2
0.50 mm
(AWG 20)
125 kbps
Lenze repeater EMF2176IB
30 m
630 m
(see Tab. 1 Total cable length (^ 53))
360 m
(see Tab. 2 Segment cable length (^ 54))
The max. segment cable length is smaller than the total
cable length to be implemented.
A repeater must be installed at the determined max.
segment cable length of 360 m.
l
6
55