Rockwell Automation 2098-IPD-xxx Ultra5000 Intelligent Positioning Drives Installation Manual - Manual (Page 94)

Publication 2098-IN001E-EN-P — April 2002
5-8 Maintaining Your Ultra5000
Node Problems
Give particular attention to the task of setting initial addresses and
data rates. Survey the network to ensure all assignments are known.
Some nodes can be logically assigned to a group of devices, but
physically located away from those devices. One incorrect node can
cause other nodes to appear to be Bus-off (Steady-Red LED). If a node
goes Bus-off and the device is reset only to go Bus-off again, the
problem is likely not with the device, but rather the setting of the
address, data rate, or a network-wide problem related to topology,
grounding, intermittent power/data connections, or electrical noise. If
a scanner goes Bus-off, nodes will not reallocate (Flashing-green or
red) even if they are functioning correctly.
Device Failure - LED Status Check
A Steady-Red Module Status LED can mean an error. If the Network
Status LED goes Steady-Red at power-up, it could mean there is a
Duplicate MAC ID. The user response is to test all devices for unique
addresses. If a Steady-Red LED remains on after the Duplicate MAC ID
test shows all devices to have a unique node address, it means a
Bus-off error. Do the following:
1. Check data rate settings.
2. If symptom persists, replace node address (with another address
and correct data rate).
3. If symptom persists, replace tee tap.
4. If symptom persists, check topology.
5. If symptom persists, check power for noise with oscilloscope or
power disturbance analyzer.