H D 2 - D M - A / D M - A M
Use Cases and Troubleshooting
Subject to reasonable modifications due to technical advances.
Copyright Fuchs, Printed in Germany
Fuchs Group • Tel.: G49 621 776-0 • USA +1 330 4253555 • Sin65 67799091 • Internet http://www.pepperl-fuchs.com
99
187630
Segment level low
alarm
• Check if the bus segment is terminated correctly
(only two terminators)
• Check that the bus segment wiring is correct
• Check that there is no ingress of dirt water (re-
sistive pole-to-pole load)
• Check if the positions of the field devices have
been changed (signal level is dependent on the
field device position, due to bus cable resis-
tance)
• Check which field device address is causing the
level alarm and replace the slave, if necessary
• Use the integrated scope function for further ex-
amination
Noise level high
alarm
• Check that the shielding and grounding of the
bus cable is correct
• Check if a correct potential equalization/ground-
ing system is installed
• Check that a correct bus cable type is used
• Check that there are no cables with high AC cur-
rents (50/60 Hz or pulsed) near by the bus ca-
bling as per good engineering practices
• Check if there is an oscillation on the bus seg-
ment (caused by some few slave configurations)
• Use the integrated scope function for further ex-
amination
Jitter level high
alarm
• Check if the bus segment is terminated correctly
• Check that the correct cabling type has been
used
• Check that a valid bus topology is used (maxi-
mum cable trunk and spur length, maximum
number of field barriers)
• FOUNDATION fieldbus only: check that a
FF-831qualified power supply type is used (im-
pedance)
• Check which field device address is causing the
jitter alarm and replace the device, if necessary
• Check that two segments are not connected in
parallel
Fault Type
Fault Clearance
