4.A2CCPU
--------------------
MELSEC-A
4.3
Fault
Detection
4.3.1 Self-dlagnosls
The self-diagnosis function checks occurrence of errors and faults by
the
A2C itself.
The A2C self-diagnosis function includes the
following:
(a) CPU error
(b) MINI link line error
(c) Remote terminal error
(1) CPU error
CPU error includes faulty A2C, battery error,
and
operation check error.
If a CPU error is detected,
the
CPU error flag (M9008) is set and
the
corresponding error code (see Table 4.8.) is set in
the
CPU error
register (09008).
(a) Operation at detecting CPU error
If a CPU
error
is
detected.
sequence
program
operation
is
processed in
the
following manner.
1) Stop
Sequence program operation stops if an error is detected.
At this time, the
outputs
(y) of
the
remote I/O module and remote
terminal module are as indicated below.
Remole
I/O
Module
. EC Mode
ON/OFF
Slelu.
of
Outpul
(y)
A2C I/O module
-
OFF
Remote I/O module for
OFF Output
ON/OFF
state Is retained
MINIS-3 link
ON OFF
Remote terminal module
-
OFF
2) Continue
Sequence program operation continues if an error is detected.
If an operation error is detected while a sequence program is
executed, an instruction causing the error is skipped to con-
tinuously execute
the
program.
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