Mitsubishi MELSEC Q Series, Programming Manual

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6.5 Program Branch Instructions
6.5.1 Pointer branch instructions
CJ, SCJ, JMP
SCJ
(1) Executes the program of the specified network label within the same POU from the next
scan after the execution command turns from OFF to ON.
(2) Executes the program in the next step when the execution command is OFF or turns from
ON to OFF.
JMP
(1) Unconditionally executes the program of the specified network label within the same POU.
Note the following points when using the jump instruction.
1. After the timer coil has turned ON, accurate measurements cannot be made if
there is an attempt to jump the timer of a coil that has been turned ON using the
CJ, SCJ or JMP instruction.
2. Scan time is shortened if the CJ, SCJ or JMP instruction is used to force a jump
to the OUT instruction.
3. Scan time is shortened if the CJ, SCJ or JMP instruction is used to force a jump
to the rear.
4. The CJ, SCJ, and JMP instructions can be used to jump to a step prior to the
step currently being executed. However, it is necessary to consider methods to
get out of the loop so that the watchdog timer does not time out in the process.
5. The device to which a jump has been made with the CJ, SCJ or JMP instruction
does not change.
6. The jump instruction can be used only for network labels within the same POU.
E xecut i on command O FF
SCJ
O N
E xecuted at eac h scan 1 scan
W h en X 3 is
ON, t h e loo p
is closed.
Exits t h e loo p wh en
X 7 is turned ON.
Jum p s to la b el P 1 9
wh en X B turns ON.
Y43 and Y49 remain
unc
h anged regardless
o f wh et h er X B and X C are
turned ON/OFF during t h e
execution o f CJ instruction.