6 DeviceNet Communications
6.3.1 Providing the Communications Power Supply
6-10
6
Step 1: Determining the Best Location for the Power Supply
from a Graph
A voltage drop occurs when a current flows through a DeviceNet special cable. The longer
the communications cable and the greater the current, the greater the voltage drop. The com-
munications power supply at each node must be 11 V DC or more. To ensure this, the rela-
tionship is plotted as shown in the graph below to find the maximum current that easily
satisfies the voltage of the communications power supply at different trunk line lengths even
if there is a voltage drop due to cable resistance.
Thick Cable
Thin Cable
Distance (m)
0
25
50
100
150
200
250
300
350
400
450
500
Max.
current
(A)
8.00
8.00
5.42
2.93
2.01
1.53
1.23
1.03
0.89
0.78
0.69
0.63
8
7
6
5
4
3
2
1
0
0
50
100
150
200
250
300
350
400
450
500
Distance (m)
Max. current (A)
Distance (m)
0
10
20
30
40
50
60
70
80
90
100
Max.
current
(A)
3.00
3.00
3.00
2.06
1.57
1.26
1.06
0.91
0.80
0.71
0.64
3
2
1
0
0
10
20
30
40
50
60
70
80
90
100
Distance (m)
Max. current (A)
Summary of Contents for OMNUC W R88A-NCW152-DRT
Page 1: ...Cat No I538 E3 1 DeviceNet Option Unit OMNUC W Series Model R88A NCW152 DRT...
Page 53: ...4 Connectors 4 5 3 DeviceNet Network Configuration Restrictions 4 22 4...
Page 97: ...5 Parameter Settings 5 3 8 Notch Signal Output Positioning 5 44 5...
Page 211: ...8 Servo Driver Settings 8 5 3 Absolute Encoder Multi turn Limit Setting 8 24 8...
Page 257: ...9 Troubleshooting 9 46 9...