Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 432

Error Processing
Operation Switching
Errors (Operation
Stops in Simplex
Mode or for Single
CPU Systems)
396
In a Duplex CPU System, the standby CPU Unit will become the active CPU
Unit and continue operation (assuming the standby CPU Unit is normal) in
RUN or MONITOR mode and in Simplex Mode whenever an error causing
operation to switch occurs. If, however, the same error occurs in the CPU Unit
that was the standby or another error that would cause operation to switch
occurs, system operation will stop.
In Simplex Mode or will a Single CPU System, all of these errors are fatal and
will cause operation to stop.
Connect the CX-Programmer or a Programming Console to display the error
message (in the PLC Error Window on the CX-Programmer). The cause of
the error can be determined from the error message and related Auxiliary
Area flags and words.
An error causing operation to switch (or a fatal error in Simplex Mode) has
occurred if the indicators have the following conditions during operation in
RUN or MONITOR mode.
Power Supply Unit
CPU Unit
With a Duplex CPU
System, the CPU
Unit that was active
when the error
occurred
Duplex Unit (Duplex
CPU System only)
The standby CPU Unit in a Duplex CPU System will have the following indica-
tor status when an error causing operation to switch occurs.
Power Supply Unit
CPU Unit that was
on standby when the
error occurred
Duplex Unit
Note With a Duplex CPU System in Simplex Mode or with a Single CPU System,
status will be as follows:
I/O memory will be cleared when any error that switches operation occurs
except for an error generated by an FALS instruction. I/O memory will not be
cleared for a FALS instruction.
If the I/O Memory Hold Bit is ON, I/O memory will be held, but outputs to all
Output Units will be turned OFF.
POWER
RUN
ERR/ALM
INH
PRPHL
COMM
DPL STATUS
Active CPU Unit ACTIVE
indicators
CPU STATUS
Standby CPU Unit ACTIVE
indicators
CPU STATUS
POWER
RUN
ERR/ALM
INH
PRPHL
COMM
DPL STATUS
Active CPU Unit ACTIVE
indicators
CPU STATUS
Standby CPU Unit ACTIVE
indicators
CPU STATUS
Section 10-2
Lit green
Not lit
Lit red
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Not lit
Not lit
CPU error: Lit red
Other: Flashing red
Lit green
Lit green
Lit green
Not lit
Lit red
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Not lit
Lit green
Lit green
Not lit
CPU error: Lit red
Other: Flashing red