Omron CJ - 09-2009 Operation Manual page 270

Examples
10-d) Monitoring and Debugging
1,2,3...
222
Using a Programming Console
The PLC can be put into MONITOR mode with a host computer running CX-
Programmer.
CX-Programmer
There are several ways to monitor and debug PLC operation, including the
force-set and force-reset operations, differentiation monitoring, time chart
monitoring, data tracing, and online editing.
Force-Set and Force-Reset
When necessary, the force-set and force-reset operations can be used to
force the status of bits and check program execution.
When a Programming Console is being used, monitor the bits with Bit/Word
Monitor or 3-word Monitor. Press the SHIFT+SET Keys to force-set a bit or
press the SHIFT+RESET Keys to force-reset a bit. The forced status can be
cleared by pressing the NOT Key.
Bit/Word Monitor display
3-word Monitor display
When CX-Programmer is being used, click the bit to be force-set or force-
reset and then select Force On or Off from the PLC menu.
Differentiation Monitor
The differentiation monitor operation can be used to monitor the up or down
differentiation of particular bits.
When a Programming Console is being used, monitor the bit with Bit/Word
Monitor. Press the SHIFT+Up Arrow Keys to specify up differentiation or press
the SHIFT+Down Arrow Keys to specify down differentiation.
Bit/Word Monitor display
When CX-Programmer is being used, follow the procedure shown below.
1. Click the bit for differential monitoring.
2. Click Differential Monitor from the PLC Menu. The Differential Monitor Di-
alog Box will be displayed.
3. Click Rising or Falling.
4. Click the Start button. The buzzer will sound when the specified change is
detected and the count will be incremented.
5. Click the Stop button. Differential monitoring will stop.
Trial Operation
Select PC, Mode, MONITOR.
Actual operation
Select PC, Mode, RUN.
Force-set:
SHIFT
Force-reset:
SHIFT
Clear:
NOT
Detect up-differentiation:
Detect down-differentiation:
Section 4-2
SET
RESET
↑
SHIFT
↓
SHIFT