ABB AC 800M Installation Manual page 60

Network Wiring
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Table 54
Data Rate
125 KB
250 KB
500 KB
Calculating the total cable length
1.
2.
60
The trunk line must be terminated at each end using a terminating resistor. For
more information, refer to
Trunk designing using thin cable has a significant impact on network power
design. For more information, refer to
lists the data rates for trunk distance and drop length.
Table 54. Data Rates for Trunk Distance and Drop Length
Trunk Distance
500 m (1640 ft)
250 m (820 ft)
125 m (410 ft)
The distance between any two points must not exceed the maximum cable
length allowed for the baud rate. Always use the longest distance between two
nodes in the network. For the cable length, refer to
For the respective cable type topology, refer to
Table 42.
The cable length allowed is calculated using the following formulas:
ThickL + 5 * ThinL < 500 m for 125 kb
ThickL + 5 * ThinL < 250 m for 250 kb
ThickL + 5 * ThinL < 125 m for 500 kb
where ThickL is the length of the thick cable and ThinL is the length of the thin
cable.
The maximum trunk line distance is measured between the two terminating
resistors.
Terminating Resistors
Table 14.
Drop Length
Maximum
6 m (20 ft)
Section 3 Installation
on page 46.
Cumulative
156 m (512 ft)
78 m (256 ft)
39 m (128 ft)
Figure 20.
Table 12, Table 22, Table
9ARD000015-600
32,