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5.1 Basic Concept of Redundant System
5.1.5 Self Diagnostics Function
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REDUNDANT SYSTEM FUNCTIONS
(b) Errors that allow selection of operation
For the following errors, the operation can be selected to "continue" or "stop" in
the PLC parameter's PLC RAS settings.
(In the parameter default settings, all errors are set to "stop".)
1) Operation error (including SFC program)
2) Extension instruction error (setting for extension in future)
3) Blown fuse
4) Module verify error
5) Intelligent program execution error
6) File access error
7) Memory card operation error
8) External power supply OFF (setting for extension in future)
As the module verify error is preset to "stop", when the error occurs, a stop error is
detected in the control system, resulting in system switching.
However, since the new control system also detects the module verify error and
stops its operation, the redundant system stops the control.
When the module verify error is set to "continue", even if the error occurs, the
system switching does not occur and the operation continues with I/O numbers
used before the error occurrence.
