Mitsubishi Electric MELSEC A Series User Manual page 101

Table 6.1 Error Code List for AnNCPU (Continue)
Error
Error
Code
Message
(D9008)
"RAM 20
ERROR"
(Checked at
power-on)
"OPE. 21
CIRCUIT
ERR"
(Checked at
power-on)
"WDT 22
ERROR"
(Checked at
the execution
of END
processing)
"SUB-CPU 23
ERROR" (During
(Checked run)
continuously) 26
(At
power-on)
"END NOT 24
EXECUTE"
(Checked at
the execution
of END
instruction)
CPU
Error and Cause
States
Stop The CPU has checked if
write and read operations
can be performed properly
to the data memory area of
CPU, and as a result, either
or both has not been
performed.
Stop The operation circuit, which
performs the sequence
processing in the CPU,
does not operate properly.
Stop Scan time exceeds watch
dog error monitor time.
(1) Scan time of user
program has been
exceeded for some
conditions.
(2) Scan time has
lengthened due to
instantaneous power
failure which occurred
during scan.
Stop Sub-CPU is out of control or
defective.
Stop
(1) When the
instruction was to be
executed, the instruction
was read as other
instruction code due to
noise or the like.
(2) The END
has changed to another
instruction code for
some reason.
88
Corrective Action
Since this CPU hardware
error, consult Mitsubishi
representative.
(1) Calculate and check the
scan time of user
program and reduce the
scan time using the
CJ
like.
(2) Monitor the content of
special register D9005
by use of peripheral
equipment. When the
content is other than 0,
line voltage is
insufficient. When the
content is other than 0,
the power voltage is
unstable.
Since this CPU hardware
error, consult Mitsubishi
representative.
Perform reset and run.
END
If the same error is
displayed again, it is the
CPU hardware error,
consult Mitsubishi
representative.
instruction
instruction or the