
6. LADDER DIAGRAM MONITOR
AND EDITOR
B–61863E/15
PMC–NB6 MANIPULATION
738
If the following functional instructions are used with their ACT
conditions (or RST conditions) are kept ON improperly, an attempt to
stop LADDER may take much time, or may not stop it actually.
D WINDR / WINDW
In case of window function of high–speed response, this will not
cause the problem even if its ACT is stuck to ON.
D EXIN
D AXCTL
This will cause the problem also when RST condition is stuck to
ON.
D JMPB
When it jumps to the LBL before JMPB itself.
D JMPC
When it jumps to the LBL which leads to reach the same JMPC
again.
When LADDER can not stop, any operation to modify LADDER
program may take much time to complete, or may not complete.
Processes such as followings will be affected by this problem:
1. Stop LADDER program by [STOP] soft key.
2. Read new LADDER program from memory card or other devices
at I/O screen while current LADDER program is running.
3. Update running LADDER program at LADDER Diagram Editor
screen, by exiting the screen with return key [<], or by [UPDATE]
soft key.
To avoid this problem, find above–mentioned functional instructions
whose ACT condition (or RST condition) is kept ON, and follow
instructions below to correct LADDER program to use these functional
instructions properly:
1. Confirm that machine is in safe condition, and then turn off
CNC’s power.
2. Turn on CNC’s power, with ”CAN” and ”Z” keys keeping held
down until CNC’s finishes starting up completely, not to run
LADDER program automatically.
3. Go to LADDER Diagram Editor screen, find the instruction that
cause the trouble, modify logic around the instruction, so that
ACT condition (or RST condition) will once turn OFF after every
time the process of the instruction completes. In case that JMPB
or JMPC repeats same process, examine the condition to jump,
and reconstruct the structure of LADDER if necessary.
4. Write LADDER program into flash ROM at I/O screen.
5. Run LADDER program.
If the problem still remains after correction, there may be another
functional instruction that causes the trouble in the same way. Repeat
finding and correcting them in the same way, until the trouble is resolved.
6.2.5
How to Correct
LADDER Program that
Never Stops