Epson RC90 User Manual

4. Troubleshooting (PROFIBUS DP)
RC700 / RC90 Option Fieldbus I/O Rev.14 307
♦ Causes of Error
Possible Cause
Examination Method
Countermeasure
 Disconnected
terminating resistors
 Cable disconnection
 Disconnected
connector
 Disconnected signal
wire
(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 details, refer to the section
4.2.3.1 Connection Problem.
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.
 Loose connector
 Loose signal wire
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.
Connect the connectors
and signal wires again.
 Broken unit
Replace the trouble unit with a new
one.
→Verify whether the problem is
fixed.
Replace the unit with a
new one.

No cause is
identified.
Identify the trouble point by
dividing the network.
→ For details, refer to the section
4.2.3.4 Broken Unit Examination.

Epson RC90 Specifications

General

Brand	Epson
Model	RC90
Category	Controller
Language	English