Epson RC90 Manual page 33

Total Drop Line Length
Total drop line length is the total distance of all drop lines in one network.
Terminating
Resistor
In the figure above, the total drop line length is 17 m.
The maximum total drop line length is restricted by baud rate as shown in the table below.
The cable thickness is not related to the restriction.
Cable Current Capacity
Current-carrying capacity of the DeviceNet network cable is restricted as below:
Current Capacity
Following figures illustrate examples of power supply configuration.
When an external power supply is installed in the network as shown in the figure below,
the current capacity is 11A and it exceeds the permissible current of the cable.
Terminating
Resistor
External Power
Supply 24 V DC
If the location of the external power supply is changed as shown in the figure below, the
power supply can be used because the current capacity on the left side of the power supply
tap is 5 A and 6 A on the right side.
Terminating
Resistor
RC700 / RC90 Option Fieldbus I/O Rev.14
2 m
2 m
1 m
4 m
3 m
1 m
Baud Rate
500 kbps
250 kbps
125 kbps
Trunk Line
Thick Cable
8A
Power Supply Tap
1A
1A 1A
Power Supply Tap
2A
External
Power Supply
1A
24 V DC
1A 1A
Trunk Line
Terminating
Resistor
4 m
Max. Total Drop Line Length
39 m
78 m
156 m
Thin Cable
3A 4.57 / Drop Line Length (m) ≤ 3A
Trunk Line
2A 2A
2A
2A
Trunk Line
2A 2A
2A
2. Installation
Drop Line (Unit: A)
Terminating
Resistor
Terminating
Resistor
21