155
Sequence Control Instructions Section 3-4
Description When the execution condition for JMP(004) is ON, no jump is made and the
program is executed consecutively as written.
When the execution condition for JMP(004) is OFF, program execution jumps
directly to the first JME(005) in the program with the same jump number. The
instructions between JMP(004) and JME(005) are not executed, so the status
of outputs between JMP(004) and JME(005) is maintained. In block programs,
the instructions between JMP(004) and JME(005) are skipped regardless of
the status of the execution condition.
Because all of instructions between JMP(004) and JME(005) are skipped
when the execution condition for JMP(004) is OFF, the cycle time is reduced
by the total execution time of the skipped instructions. In contrast, NOP(000)
processing is performed for instructions between JMP0(515) and JME0(516),
so the cycle time is not reduced as much with those jump instructions.
The following table compares the various jump instructions.
Flags (JMP)
Precautions All of the outputs (bits and words) in jumped instructions retain their previous
status. Operating timers (TIM, TIMX(550), TIMH(015), TIMHX(551),
TMHH(540), and TMHHX(552)) continue timing because the PVs are updated
even when the timer instruction is not being executed.
When there are two or more JME(005) instructions with the same jump num-
ber, only the instruction with the lower address will be valid. The JME(005)
with the higher program address will be ignored.
Instructions in this section are not
executed and output status is
maintained. The instruction execution
time for these instructions is eliminated.
Instructions
jumped
Execution condition
Instructions
executed
Item JMP(004)
JME(005)
CJP(510)
JME(005)
CJPN(511)
JME(005)
JMP0(515)
JME0(516)
Execution condition for jump OFF ON OFF OFF
Number allowed 256 total No limit
Instruction processing when jumped Not executed. NOP(000) processing
Instruction execution time when
jumped
None Same as NOP(000)
instructions
Status of outputs (bits and words)
when jumped
Bits and words maintain their previous status.
Status of operating timers when
jumped
Operating timers continue timing.
Processing in block programs Always jump. Jump when ON. Jump when OFF. Not allowed.
Name Label Operation
Error Flag ER ON if N is not within the specified range of 0 to 255 (0000
to 00FF hex).
ON if there is a JMP(004) in the program without a
JME(005) with the same jump number.
ON if there is a JMP(004) in the task without a JME(005)
with the same jump number in the task.
OFF in all other cases.
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