144
Overview of I/O Memory Area
Section 4-1
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.
Auxiliary Area Flags and Words
PLC Setup
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.
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.
Name
Description
Setting
Default
IOM Hold
Bit Status
at Startup
To retain all data in I/O
memory when the PLC
is turned ON, set the
IOM Hold Bit at startup
parameter to hold the
status of the I/O Hold Bit.
OFF:
The IOM Hold Bit is cleared
to 0 when power is cycled.
ON:
The status of the IOM Hold
Bit is retained when power is
cycled.
OFF
(Cleared)
Retained
Power ON
I/O memory
CIO and
other areas
Summary of Contents for CP1L CPU UNIT - 03-2009
Page 1: ...Cat No W462 E1 06 CP1L CPU Unit SYSMAC CP Series CP1L L_0D_ CP1L M_0D_ OPERATION MANUAL...
Page 2: ......
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Conformance to EC Directives 6...
Page 70: ...36 Function Blocks Section 1 5...
Page 584: ...550 Trouble Shooting Section 8 7...
Page 627: ...593 Sample Application Section 9 12 Network Settings Network Tab Network Settings Driver Tab...
Page 630: ...596 Sample Application Section 9 12...
Page 654: ...620 Troubleshooting Unit Errors Section 11 4...
Page 662: ...628 Replacing User serviceable Parts Section 12 2...
Page 668: ...634 Standard Models Appendix A...
Page 698: ...664 Auxiliary Area Allocations by Function Appendix C...
Page 746: ...712 Auxiliary Area Allocations by Address Appendix D...
Page 773: ...739 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 774: ...740 Connections to Serial Communications Option Boards Appendix F...
Page 806: ...772 Index...
Page 808: ...774 Revision History...