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Error Classification and Confirmation Section 11-1
11-1 Error Classification and Confirmation
Error Categories
Errors in CP1H CPU Units can be broadly divided into the following four cate-
gories.
Confirming Errors
There are three sources of information on errors that have occurred.
• CPU Unit indicators
• Seven-segment display
• Auxiliary Area
CPU Unit Indicators
These indicators show the operating status of the CPU Unit.
Note Do not turn OFF the CPU Unit power supply when this indicator is lit.
Category Comments
CPU Error A WDT (watchdog timer) error is generated in the CPU Unit, the
CPU Unit will malfunction, and operation will stop.
CPU Standby The CPU will go on standby because conditions for stating oper-
ation have not yet been met.
Fatal Error Operation cannot continue. Operation will stop due to a serious
problem.
Non-fatal Error A minor problem has occurred. Operation will continue
POWER RUN
INH
PRPHLBKUP
ERR/ALM
POWER
(green)
Lit Power is ON.
Not lit Power is OFF.
RUN (green) Lit The CPU Unit is executing a program in either RUN or
MONITOR mode.
Not lit Operation is stopped in PROGRAM mode or due to a
fatal error.
ERR/ALM
(red)
Lit A fatal error or CPU error (WDT error) has occurred.
operation will stop and all outputs will be turned OFF.
Flashing A non-fatal error has occurred. Operation will continue.
Not lit Operation is normal.
INH (yellow) Lit The Output OFF Bit (A500.15) was turned ON. All out-
puts will be turned OFF.
Not lit Operation is normal.
BKUP
(yellow)
(See note.)
Lit The built-in flash memory is being written to or the
Memory Cassette is being accessed.
The BKUP indicator also lights while the user program
is being restored when the power supply is turned ON.
Not lit Other than the above.
PRPHL
(yellow)
Flashing Communications (either sending or receiving) are in
progress through the peripheral port.
Not lit Other than the above.