Epson RC90 - Page 291

4. Troubleshooting (DeviceNet)
RC700 / RC90 Option Fieldbus I/O Rev.14 279
♦ Process Flowchart
Check that
terminating resistors
are connected.
Measure resistance
with tester.
50 to 70 Ω
Normal
See 4.1.3.2.
Turn OFF communications power supply.
Normal
Resistance: over 70 Ω
Remove one terminating
resistor on either side.
Measure
resistance at
connectors and
branch taps with
tester.
Resistance: under 50 Ω
Problem exists.
(Add terminating resistors.)
Out of 50 to 70 Ω (Error)
Yes
Other
Approx.
120
Ω
10 to 50Ω
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 circuit
between signal
wires
Check for cable laying.
Find the trouble point.
Check for connection
with terminating resistors
and branch taps.
Check for short
circuit between
signal wires.