Yaskawa SmartTrac DeviceNet Card - Manual (Page 30)

SMART TRAC DeviceNet Card
26
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Troubleshooting Your Smart Trac DeviceNet Card Technical Manual 3554-0070
•
Look for patterns in the symptoms. Do intermittent problems occur
when other un-related equipment is in use?
•
Do some nodes communicate correctly? What is the difference
between the functioning nodes and the others (proximity to the
power supply, to the terminator, to the scanner)?. Is the device
improperly shielded or tied to ground at each device instead of at
ends?
Table 6. Hardware Configuration Troubleshooting.
Troubleshooting Hardware Configuration
Symptom
Probable
Cause
Corrective Action
Devices will
not
communicate Baud rate
not same for
all devices Check that baud rate is set correctly for
each device on the network.
MAC IDs not
unique for
each device
on network. Check MAC Ids for all devices on the
network.
Faulty
devices Opens or
shorts in the
network
wiring Check for faulty connectors or cable.
Incorrect
Baud Rates
on some
devices Check that baud rate is set correctly for
each device on the network.
Electrical
interference Check for incorrect grounding or broken
shield.
Signal
distortion &
attenuation Check for improper termination such as a
failure to adhere to topology guidelines,
or faulty connectors or loose terminal
blocks.
Missing
terminators Excessive
common
mode
voltage Check for excess current or cable length.
Check for faulty connectors.
Low power
supply
voltage Check for excess current or cable length
Check for faulty connectors
Check that power supply is correctly
sized for number of devices in network
Excessive
signal
propagation
delay Check for excess cable length.