Pepperl+Fuchs HD2-DM-A Manual page 183

Advanced Diagnostics
Appendix
ID
212
213
215
216
217
218
219
220
182
Phenomenon
Segment voltage is mea-
sured as zero. Segment is
unpowered
Segment voltage is "Out of
specification"
Noise is MR/OOS for the
segment
Noise of one device is
MR/OOS, value is not
MR/OOS of other devices
Jitter is MR/OOS for the
segment
Jitter of one device is
OOS/MR, jitter of other
devices is OK
Unbalance is MR/OOS to
the positive pole
Unbalance is OOS/MR to
the negative pole
Cause(s)
Trunk short circuit
Fieldbus power supply
failed
Fieldbus power supply
removed
Terminal failure: loose con-
nection
Diagnostic device is
wrongly or not connected
to the segment
Power supplies failed for
the segment
Noise injection on the field-
bus
Shield wiring / grounding
fault
Device injects noise
Fieldbus impedance fault
Not enough terminators
Device malfunction: jitter of
a device is too high
Not enough terminators
Fieldbus impedance fault
Short circuit/leakage cur-
rent between fieldbus pos.
pole and shield/ground
Water ingress
Short circuit/leakage cur-
rent between fieldbus neg.
pole and shield/ground
Water ingress
Action(s)
Check trunk. If no spur
short circuit protection is
installed, also check spurs.
Replace fieldbus power
supply module
Install fieldbus power sup-
ply
Check all terminals for cor-
rect connection
Check wiring connection to
the segment
Check and replace fieldbus
power supplies
Check fieldbus cable for
correct shielding and
grounding. Check for exter-
nal noise sources.
Check fieldbus cable for
correct shielding and
grounding.
Check noise with the field-
bus oscilloscope. The
device showing high noise
values is not necessarily
the one injecting the noise.
Check if the fieldbus topol-
ogy is valid. Check noise,
reduce high noise values.
Check if a terminator is
installed on both ends of
the trunk
Replace device
Check if a terminator is
installed on both ends of
the trunk
Check if the fieldbus topol-
ogy is valid. Check noise,
reduce high noise values.
Remove connection
between pos. pole and
shield/ground
Check housings of devices
and junction boxes for
water ingress
Remove connection
between neg. pole and
shield/ground
Check housings of devices
and junction boxes for
water ingress