Epson EM07ZS1647F User Manual page 141

♦ Causes of Error
Possible Cause
Disconnected
terminating
resistors
Cable
disconnection
Disconnected
connector
Disconnected
signal wire
Loose connector
Loose signal wire
Broken unit
No cause is
identified.
Fieldbus I/O Rev.6
Examination Method
(1) Check that terminating
resistors are connected to both
ends of the network.
(2) Measure resistance between
signal wires with device
power supply OFF.
→ Normal: 100 to 120 Ω
Measuring point: Connection of
the trouble unit
For detail, refer to the section
4.2.3.1 Connection Problem.
Check for the connection of
connectors and signal wires.
→ The connectors and signal
wires should be firmly
connected.
Checkpoint: all stations and all
branch taps
For details, refer to the section
4.2.3.2 Loose Connector and
Signal Wire.
Replace the trouble unit with a
new one.
→ Verify whether the problem is
fixed.
Identify the trouble point by
dividing the network.
→ For details, refer to the section
4.2.3.4 Broken Unit
Examination.
4. Troubleshooting (PROFIBUS DP)
Countermeasure
Fix the problem.
How to find the trouble
point:
Remove the terminating
resistor on one end of the
network. The trouble point
is where resistance changes
from 220 Ω .
Connect the connectors and
signal wires again.
Replace the unit with a
new one.
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