Omron CP1L-EL20DR-D, Operation Manual

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Overview of I/O Memory Area Section 4-1
4-1-4 Hot Start/Hot Stop Functions
Operating Mode Changes
Hot Start
Turn ON the IOM Hold Bit to retain all data* in I/O memory when the CPU Unit
is switched from PROGRAM mode to RUN/MONITOR mode to start program
execution.
Hot Stop
When the IOM Hold Bit is ON, all data* in I/O memory will also be retained
when the CPU Unit is switched from RUN or MONITOR mode to PROGRAM
mode to stop program execution.
Note *The following areas of I/O memory will be cleared during mode changes
(between PROGRAM and RUN/MONITOR) unless the IOM Hold Bit is ON:
the CIO Area (I/O Area, Data Link Area and Internal I/O Areas), Work Area,
Timer Completion Flags, and Timer PVs.
Auxiliary Area Flags and Words
When the IOM Hold Bit is ON, all outputs from Output Units will be maintained
when program execution stops. When the program starts again, outputs will
have the same status that they had before the program was stopped and
instructions will be executed. (When the IOM Hold Bit is OFF, instructions will
be executed after the outputs have been cleared.)
PLC Power ON In order for all data* in I/O memory to be retained when the PLC is turned ON,
the IOM Hold Bit must be ON and it must be protected in the PLC Setup using
the IOM Hold Bit Status at Startup parameter.
PROGRAM
Retain
I/O memory
CIO and
other areas
MONITOR or RUN
PROGRAM
Retain
MONITOR or RUN
I/O memory
CIO and
other areas
Name Address Description
IOM Hold Bit A500.12 Specifies whether the I/O memory will be retained or not
when the CPU Unit operating mode is changed
(between PROGRAM and RUN/MONITOR) or when the
power is cycled.
OFF: I/O memory is cleared to 0 when the operating
mode is changed.
ON: I/O memory is retained when the operating mode
is changed between PROGRAM and RUN or
MONITOR.
Retained
Power ON
I/O memory
CIO and
other areas