Epson RC90 - Page 321

4. Troubleshooting (PROFIBUS DP)
RC700 / RC90 Option Fieldbus I/O Rev.14 309
♦ Process Flowchart
Normal
See 4.2.3.2.
Turn OFF all units.
Normal
Resistance: over 120 Ω
Measure
resistance at
connectors
with tester.
Resistance: under 100 Ω
Problem exists.
(Add terminating resistors.)
Out of 100 to 120 Ω (Error)
Yes
Other
Approx.
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 circuit
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 short
circuit between
signal wires.