Check the Power Section 4 Troubleshooting
76 9ARD000015-600
Check the Power
• Check trunk and drop current limits.
• Check type (size and length) of cable bringing power into the trunk.
• Measure the 24V supply at the middle and ends of the network.
• Consider spot checking the power for noise with an oscilloscope.
• The 24 VDC Network Power for DeviceNet Must be for the DeviceNet
network only.
Check the Wiring
• Check lead dress in junction boxes.
• Check that connectors are screwed together tightly.
• Check that glands are screwed tightly.
• Check for foreign material (electrical tape, RTV, etc.) in glands.
• Check that nodes are not touching extremely hot or cold surfaces.
• Check that cables are kept a few inches away from power wiring.
• Check that cables are not draped on electric motors, relays, contactors or
solenoids.
• Check that cables are not constrained so as to place excessive tension on
connectors.
• Wiggle connectors to provoke intermittent failures.
Check the Scanner Configuration
•Baud Rate.
• Node Address.
Check the Nodes
• Drop 24V supply, re-power and reset the scanner to initialize the network.
• Examine the scanner display codes to identify problem nodes.
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