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Checking Operations for CS-series, C200HX/C200HG/C200HE-(Z)E, and C200HS Master Units
Section 6-2
6-2
Checking Operations for CS-series, C200HX/C200HG/
C200HE-(Z)E, and C200HS Master Units
6-2-1
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.
Communications Error
Node Number Indicators
(C200HW-SRM21-V1 Only)
When a communications error occurs with a Slave during communications
and the ERC indicator lights, the other indicators will show the node number
of the Slave where the error occurred in binary.
When several communications errors occur simultaneously, the node number
of the Slave with the first recognized communications error will be displayed.
The display will not be changed if another communications error occurs while
a node number is already being displayed. A new node number can be dis-
played after the first communications error is cleared.
When a communications error occurs in a 16-point or greater Slave, any of
the node numbers currently used by that Slave may be displayed.
Situation
Indicator status
Probable cause
Possible remedy
RUN
ERC
SD
RD
Normal communica-
tions
ON
OFF
ON
ON
---
---
PLC’s power OFF
OFF
OFF
OFF
OFF
The PLC’s power is OFF.
Turn the PLC’s power supply ON.
Not connected to
Backplane
OFF
OFF
OFF
OFF
The Master is not completely
connected to the Backplane.
Mount the Master properly.
CPU Unit standby sta-
tus
OFF
OFF
OFF
OFF
One of the Special I/O Units is
faulty.
Replace the faulty Unit, which will be
indicated by a“$” in the I/O table.
Special I/O Unit error
OFF
OFF
OFF
OFF
Refreshing between the PLC
and Master Unit is not being
performed properly.
After correcting the cause, toggle the
Unit’s restart bit in the AR Area.
Replace the Unit if it doesn’t reset
when the restart bit is toggled.
I/O UNIT OVER error
OFF
OFF
OFF
OFF
The same unit number has
been set on two or more Spe-
cial I/O Units.
An out-of-range unit number
has been set.
Set unique unit numbers.
If the usable node numbers are
within IN0 to IN15 and OUT0 to
OUT15, 9 or F cannot be set. node
numbers A to F cannot be used with
C200HX-CPU3
@
-(Z)E/ -CPU4
@
-
(Z)E, C200HG-CPU3
@
-(Z)E/ -
CPU4
@
-(Z)E, or C200HS PLCs.
I/O BUS error
OFF
OFF
OFF
OFF
The I/O bus is not connected
correctly. (In CS-series PLCs,
an I/O BUS error may have
occurred in another Unit.)
Check the I/O connecting cables
between all Racks. Clear the error
after the connection is fixed.
Slave not connected
ON
OFF
ON
OFF
No Slaves are connected, or
the communications mode of
each Slave does not match
that of the Master Unit.
Use a Slave that can communicate
properly, or make the communica-
tions mode of each Slave match that
of the Master Unit.
Communications error
with a Slave
ON
ON
ON
---
An error has occurred with a
Slave during communications
and it is withdrawn from the
system.
Check the Communications Error
Flags or indicators and clear the
cause of the communications error.
See
Communications Error Node
Number Indicators
below.
