Mitsubishi Electric QJ71DN91, User Manual

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MELSEC-Q
5 SETUP AND PREPARATION
(4) When using both trunk and drop lines
The current capacity is calculated as shown below when the network power
supply unit is connected to a network that has a 200m-long trunk line of thick
cables and a 6m-long drop line of a thin cable.
1.0A
Network power
supply unit
0.15A 0.05A 0.25A
200m
0.1A
Terminating
resistor
Master node Slave node Slave node Slave node
Terminating
resistor
Slave node
Total thick-cable length = 200m
Total drop-line length = 6m
Total current capacity = 0.5A + 0.15A + 0.05A + 0.25A + 0.1A = 1.05A
Max. current capacity available for thick cable length of 200m (See Table 5.4.) =
1.53A
Max. current capacity available for thin cable length of 6m (See Table 5.6.) =
0.75A
Total current consumed by devices connected to drop line = 0.1A
Therefore, this configuration allows power supply to all nodes.
Table 5.6 Maximum current capacity for each drop line length
Drop line length (m) 0.30 0.90 1.50 2.25 3.00 4.50 6.00
Max. current (A) 3.00 3.00 3.00 2.00 1.50 1.00 0.75