55
CPU Unit Operating Modes
Section 2-5
(2) The forced status held or cleared according to the status of the Force Sta-
tus Hold Bit and the setting for Forced Status Hold Bit Status at Startup
in the PLC Setup (read only when power is turned ON).
Note
When the mode is changed between PROGRAMMING mode and
RUN or MONITOR mode, forced status initialization is according to
the status of the Forced Status Hold Bit at that time.
(3) User program recovery is performed if online editing is performed but the
power supply to the PLC is turned OFF before the CPU Unit can complete
backup processing. The BKUP indicator will light during backup process-
ing.
2-5
CPU Unit Operating Modes
2-5-1
Operating Modes
The CPU Unit has three operating modes that control the entire user program
and are common to all tasks.
PROGRAM:
Programs are not executed and preparations, such as initial-
izing the PLC Setup and other settings, transferring pro-
grams, checking programs, force-setting and force-resetting
can be executed prior to program execution.
MONITOR:
Programs are executed, but some operations, such as online
editing, forced-set/reset, and changes to present values in I/O
memory, are enabled for trial operation and other adjust-
ments.
RUN:
Programs are executed and some operations are disabled.
2-5-2
Status and Operations in Each Operating Mode
The following table lists status and operations for each mode.
Auxiliary bit
PLC Setup setting
Forced Status Hold Bit (A500.13)
Clear (OFF)
Hold (ON)
Forced Status Hold
Bit Status at Startup
Clear
(OFF)
At power ON: Clear
At mode change: Clear
At power ON: Clear
At mode change: Hold
Hold
(ON)
At power ON: Hold
At mode change: Hold
Operation
PROGRAM mode
RUN mode
MONITOR mode
Program execution
Stopped
Executed
Executed
I/O refreshing
Executed
Executed
Executed
External I/O status
OFF
According to program
According to program
I/O memory
Non-holding memory
Cleared
According to program
According to program
Holding memory
Held
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......