Epson RC620 Manual page 162

4. Troubleshooting (DeviceNet)
♦ Causes of Error
 Voltage drop of
 Disconnected
 Cable
 Disconnected
 Disconnected
 Loose connector
 Loose signal wire
 All slaves power
 Master unit
152
Possible Cause
Measure voltage of
communications communications power supply at
power supply the master unit.
→ Normal: 11V or more between
 If the voltage is 11 to 14 V, the
(1) Check that terminating
terminating
resistors
(2) Measure resistance between
disconnection
connector
→ Normal: 50 to 70Ω
 Measuring point: Connection
signal wire
 For details, refer to the section
Check for the connection of
connectors and signal wires.
→ The connectors and signal
 Checkpoint: Between the
 For details, refer to the section
Measure the power voltage of the
OFF slaves. (It should be within the
range of sufficient voltage for
slave operation.)
(1) Start applicomIO Console
configuration
(2) Check that the configuration
 For details, refer to the section
Examination Method
V+ and V-
master unit is a possible cause.
Fix the problem on it.
resistors are connected to
both ends of the network.
signal wires with
communications power
supply OFF.
of the master
4.1.3.1 Connection Problem.
wires should be firmly
connected.
master and its slaves
4.1.3.2 Loose Connector and
Signal Wire.
application and check that the
configuration has
difference with the network
condition.
data were written in flash.
4.1.3.6 EPSON RC+ Master
Configuration.
Countermeasure
Check voltage of the power
supply.
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 120 Ω.
Connect the connectors
and signal wires again.
Supply power to the slaves.
Change the configuration.
no
RC620 Option Fieldbus I/O Rev.8