4. Troubleshooting (PROFIBUS DP) ♦ Process Flowchart
Normal
See 4.2.3.2.
Turn OFF all units.
Normal Resistance: over 120
Ω
Measure
resistance a
t
connectors
with tester.
Resistance: under 100 Ω
Problem exists.
(Add terminating resistors.)
Out of 100 to 120 Ω (Error)
Yes
Other
A
pprox.
220 Ω
10 to 100 Ω
Under 10 Ω
No
(1) Unconnected or loose connector
(2) Cable disconnection, etc.
(1) Three or more
terminating resistors
(2) Wrong terminating
resistors, etc.
Short circui
t
between signal
wires
Check for cable laying.
Find the trouble point.
Check for connection
of terminating resistors.
Check that
terminating resistors
are connected.
Measure resistance
with tester.
100 to 120 Ω
Remove one terminating
resistor on either side.
Check for shor
t
circuit between
signal wires.
Fieldbus I/O Rev.6 131