Pepperl+Fuchs HD2-DM-A Manual page 177

Advanced Diagnostics
Appendix
ID
134
135
136
137
138
140
141
142
144
145
176
Phenomenon
Noise of one device is "Out
of specification", noise is
not "Out of specification"
for other devices
Jitter of one device is "Out
of specification", jitter is not
"Out of specification" for
other devices
Signal level of one device
is too low for the given
topology, signal level of
others is OK
Segment powered and OK
but no communication
detected
Segment Power Supply
Module (A or B) not
installed
Noise is "Out of specifica-
tion" for the segment
Jitter is "Out of specifica-
tion" for the segment
Current is too high for the
fieldbus power supply
Signal level is too high,
only host is active and seg-
ment is powered
Signal level of one or more
devices is too high and
devices are missing com-
pared to commissioning
Cause(s)
Device injects noise
Device malfunction: jitter of
a device is too high
Not enough terminators
Fieldbus impedance fault
Device malfunction: Signal
level is too low
Too many terminators
Host/LAS/master commu-
nication fault
No host connected
Segment Power Supply
Module (A or B) not
installed
Shield wiring / grounding
fault
Noise injection on the field-
bus
Fieldbus impedance fault
Wrong cable type, cable
impedance not correct
Not enough terminators
Fieldbus power supply
overload
Trunk breakage between
fieldbus power supply and
first device coupler
Trunk breakage between
device couplers
Not enough terminators
Action(s)
Check noise with the field-
bus oscilloscope. The
device showing high noise
values is not necessarily
the one injecting the noise.
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.
Replace device
Check that one terminator
is installed on each end of
the trunk cable, but no
more than these two in total
Check host/LAS/master
Check if the host is
installed and correctly con-
nected to the segment
Install Segment Power
Supply Module (A or B) on
the motherboard
Check fieldbus cable for
correct shielding and
grounding.
Check fieldbus cable for
correct shielding and
grounding. Check for exter-
nal noise sources.
Check if the fieldbus topol-
ogy is valid. Check noise,
reduce high noise values.
Check if the correct cable
is installed and the cable
can be used for the topol-
ogy
Check if a terminator is
installed on both ends of
the trunk
Check if there is any con-
nection between fieldbus +
and fieldbus - or remove
devices
Check trunk, fieldbus
power supply terminals
and first device coupler
Check trunk cable and
device coupler terminals
Check if a terminator is
installed on both ends of
the trunk