Rockwell Automation 2098-IPD-020-DN Ultra5000 Series Intelligent Positioning Drives with DeviceNet Reference Manual - Manual (Page 83)

Publication 2098-RM002A-EN-P – October 2001
Troubleshooting DeviceNet Drives 5-5
Cable Installation and
Design Problems
Cable installation and design refers to the physical layout and
connections on the network. Walk the network if possible to
determine the actual layout and connections. Network management
software displays only a logical record of the network. Ensure that
you have a diagram of the physical layout and a record of the
information from the tables below.
Adjusting the Physical
Network Configuration
Ways to improve the efficiency of your physical network configuration
include:
• Shortening the overall length of the cable system
• Moving the power supply in the direction of an overloaded cable
section
• Moving devices from an overloaded cable section to a less loaded
section
• Moving higher current loads closer to the power supply
• Adding another power supply to an overloaded network
• Moving the power supply from the end to the middle of the
network
Cable Checks Power Checks
Number of nodes Break the earth ground of the V- and Shield and verify
>1.0 Mohm to frame ground with power supply off
Individual drop lengths Use a multi-meter to check for short circuit between
CAN_H and CAN_L, or CAN (H or L) to Shield, V- or V+
Branched drop length Total power load and at its distribution points
Cumulative drop length Spot check power for noise
Total trunk length
Power supply cable
length and gauge
Terminator locations
and size