GE VersaMax PLC, User Manual

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%I0002
%I0001 %Q0001
%R0001
MCRN
FIRST
ADD_
INT
I1
I2
Q
1
%R0001
ENDMCRN
FIRST
%I0003 %Q0003
%I0004 %Q0004
S
10.2.5 Control Functions Jump, Label
The Nested Jump instruction causes a portion of the program logic to be bypassed.
Program execution continues at the Label specified. When the Jump is active, all coils
within its scope are left at their previous states. This includes coils associated with timers,
counters, latches, and relays.
The Nested Jump instruction has the form ———>>LABEL01, where LABEL01 is the
name of the corresponding nested Label instruction.
A nested Jump can be placed anywhere in a program.
There can be multiple nested Jump instructions corresponding to a single nested Label.
Nested Jumps can be either forward or backward Jumps.
There can be nothing after the Jump instruction in the rung. Power flow jumps directly
from the instruction to the rung with the named label.
Caution
To avoid creating an endless loop with forward and
backward Jump instructions, a backward Jump
must contain a way to make it conditional.
10.2.5.1 Label
The Label instruction is the target of a Jump. Use the Label instruction to resume normal
program execution. There can be only one Label with a particular name in a program.
The Label instruction has no inputs and no outputs; there can be nothing either before or
after a Label in a rung.
10.2.5.2 Example Jump and Label Instructions
In the example, whenever Jump TEST1 is active, power flow is transferred to Label
TEST1.
With a Jump, any function blocks between the Jump and the Label are not executed, and
coils are
not affected . In the example, when %I0002 is ON, the Jump is taken. Since the
logic between the Jump and the Label is skipped, %Q0001 is unaffected (if it was ON, it
remains ON; if it was OFF, it remains OFF).
Instruction Set Reference GFK-1503E User Manual 143
For public disclosure