143
Overview of I/O Memory Area
Section 4-1
4-1-3
Clearing and Holding I/O Memory
Note
1.
Mode changed from PROGRAM to RUN/MONITOR or vice-versa.
2.
The PLC Setup’s
IOM Hold Bit Status at Startup
setting determines wheth-
er the IOM Hold Bit’s status is held or cleared when the PLC is turned ON.
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, CPU Bus Unit Area, Special I/O Unit
Area, DeviceNet (CompoBus/D) Area, and Internal I/O Areas), Work Area,
Timer Completion Flags, and Timer PVs.
Area
Mode changed
1
Fatal error generated
PLC power turned ON
Execution of FALS
Other fatal errors
PLC Setup set to
clear IOM Hold Bit
status
2
PLC Setup set to
hold IOM Hold Bit
status
2
IOM Hold
Bit OFF
IOM Hold
Bit ON
IOM Hold
Bit OFF
IOM Hold
Bit ON
IOM Hold
Bit OFF
IOM Hold
Bit ON
IOM Hold
Bit OFF
IOM Hold
Bit ON
IOM Hold
Bit OFF
IOM Hold
Bit ON
CIO
Area
I/O Area
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
Serial PC Link Area
Internal I/O Area
Work Area (W)
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
Holding Area (H)
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Auxiliary Area (A)
Status treatment depends on address.
Data Memory Area (D)
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Timer Completion Flags (T)
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
Timer PVs (T)
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
Counter Completion Flags (C)
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Counter PVs (C)
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Retained
Task Flags (TK)
Cleared
Cleared
Retained
Retained
Cleared
Cleared
Cleared
Cleared
Cleared
Cleared
Index Registers (IR)
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
Data Registers (DR)
Cleared
Retained
Retained
Retained
Cleared
Retained
Cleared
Cleared
Cleared
Retained
PROGRAM
Retain
I/O memory
CIO and
other areas
MONITOR or RUN
PROGRAM
Retain
MONITOR or RUN
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...