85
CPU Unit Operating Modes Section 2-5
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.
Note The following table shows the relationship of operating modes to tasks.
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
CX-Programmer
operations
I/O memory monitoring OK OK OK
Program monitoring OK OK OK
Program
transfers
From CPU Unit OK OK OK
To CPU Unit OK XX
Checking program OK XX
Setting PLC Setup OK XX
Changing program OK X OK
Force-setting/resetting OK X OK
Changing timer/counter SV OK X OK
Changing timer/counter PV OK X OK
Change I/O memory PV OK X OK
Mode Cyclic task status Interrupt task
status
PROGRAM Disabled status (INI) Stopped
To Next Page
Loading...
