365
Checking Operations of CS-series and CJ-series Master Units
Section 6-3
6-3
Checking Operations of CS-series and CJ-series Master
Units
6-3-1
Indicators
Errors and Troubleshooting
Note
Check the system’s operation with just one Slave connected (one Slave at a
time) if the CompoBus system does not operate but the Master’s indicator sta-
tus does not match any of those in the table.
6-3-2
Checking Status Using Status Information
When using a CS-series or CJ-series Master Unit, information on active Slave
status and communications error status is stored for each Slave in the status
area of the PLC's Special I/O Unit Area.
Situation
Indicator status
Probable cause
Possible remedy
RUN ERH ERC
SD
RD
Normal communica-
tions
ON
OFF OFF ON
ON
---
---
PLC’s power OFF
OFF
OFF OFF OFF OFF The PLC’s power is OFF.
Turn the PLC’s power supply ON.
The correct voltage is not
being supplied to the PLC.
Supply the correct voltage to the
PLC.
The Master Unit is faulty.
Replace the Master Unit.
The PLC is faulty.
Replace the PLC (CPU Unit,
Power Supply Unit).
Unit number setting
error
OFF
ON
OFF OFF OFF The same unit number is set
on another Special I/O Unit,
or the unit number is not
within the specified range for
Special I/O Units.
Set unit numbers that are unique
and within the specified range.
The Master Unit was
restarted after changing the
usable node number setting
switch (DIP switch pin 1).
Restart the PLC and set to auto-
matically create I/O tables.
The CPU Unit is faulty.
Restart the PLC. If the same error
occurs, replace the CPU Unit.
Master Unit error
OFF
OFF ON
OFF OFF The Master Unit is faulty.
Replace the Master Unit.
CPU Unit error
---
ON
---
---
---
An error has occurred in the
CPU Unit.
Remove the cause of the error,
and restart the PLC. If the same
error occurs, replace the CPU Unit.
Communications
error
ON
---
ON
---
---
A Slave disconnection has
been detected.
Remove the cause of the error. In
communications stop mode, turn
ON the power or restart the Unit
after removing the cause of the
error. In normal communications
mode, the Unit will restart automat-
ically.
The Master Unit is faulty.
Restart the Master Unit. If the
same error occurs, replace the
Master Unit.
Verification error
ON
---
ON
ON
---
When the Slave registration
function is used indicates
detection of a Slave that is
missing in the network or an
unregistered Slave that is in
the network.
When a Slave is missing, the Unit
will restart automatically when the
missing Slave is connected to the
network. When an unregistered
Slave is detected, restart the Mas-
ter Unit after removing the unregis-
tered Slave.