Omron Sysmac CJ Series, Operation Manual

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Error and Alarm Processing Section 5-1
5-1-4 Errors Originating in the CPU Unit
The ERH Indicator will light when the Temperature Control Unit cannot oper-
ate normally because I/O refreshing is not being performed properly with Spe-
cial I/O Units. An error in the CPU Unit or I/O bus can interfere with I/O
refreshing.
ERH Indicator Lit and RUN Indicator Lit
The ERH and RUN Indicators will both be lit when I/O refreshing is not being
performed properly. Refer to the
CJ-series Programmable Controllers Opera-
tion Manual (W393) for details.
ERH Indicator Lit and RUN Indicator Not Lit
If a WDT (watchdog timer) error occurred in the CPU Unit because the Tem-
perature Control Unit’s unit number was set incorrectly or there was an error in
the I/O bus, the ERH Indicator will light since I/O refreshing will not be per-
formed properly with the Temperature Control Unit.
5-1-5 Special I/O Unit Restart Bits
After changing the contents of DM settings or eliminating the cause of an
error, the Unit must be restarted by turning the PLC’s power ON again or tog-
gling (OFF
→
ON
→
OFF) the corresponding Special I/O Unit Restart Bit.
Lit
RUN
ERC
ERH
Not lit
Error Cause Control status Processing
CPU Unit Monitor
Error A response was not
returned from the CPU Unit
within the fixed interval. Control operation
will continue. Check the I/O refreshing interval.
Lit
RUN
ERC
ERH
Not lit
Error Cause Control status Processing
Unit Number Dupli-
cation Error The Temperature Control Unit’s unit number is
duplicated on another Special I/O Unit or is not
within the allowed range (00 to 94).
(The Temperature Control Unit occupies 20
words in the Special I/O Unit Area, so it is also
possible that these allocated words overlap.)
Control operation
will stop. Correct the unit number set-
tings. Turn the power ON
again or restart the Unit.
Special I/O Unit
Setup Error An installed Special I/O Unit does not match
the Special I/O Unit registered in the I/O table.
I/O Bus Error An error occurred in the transfer of data
between the CPU Unit and another Unit. Check that the sliding latches
connect all of the Units
securely and the End Cover is
locked. Turn the power ON
again or restart the Unit.
CPU Unit WDT Error An error occurred in the CPU Unit