197
3. Instructions
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Sequence Control Instructions
3
JMP/JME
Function
Hint
• Because all of instructions between JMP(004)/CJP(510)/CJPN(511) 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, processing time equivalent to NOP(000) processing is
required 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.
Precautions
When the execution condition for JMP(004) is ON, no
jump is made and the program is executed consecu-
tively 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 con-
dition.
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 1,024 total (256 for CJ1M-CPU11/21.) No limit
Instruction processing when
jumped
Not executed. NOP(000) processing
Instruction execution time when
jumped
None Equivalent to
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.
• 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), TMHHX(552), TIMU(541),
TIMUX(556), TMUH(544), and TMUHX(557)) continue timing because the PVs are updated even
when the timer instruction is not being executed.
Error will occur in the present value of any active TIMU(541), TIMUX(556), TMUH(544),
TMUHX(557) instruction when the instruction is jumped.
• When there are two or more JME(005)
instructions with the same jump number, only
the instruction with the lower address will be
valid. The JME(005) with the higher program
address will be ignored.
• When JME(005) precedes JMP(004) in the
program, the instructions between JME(005)
and JMP(004) will be executed repeatedly as
long as the execution condition for JMP(004)
is OFF. A Cycle Time Too Long error will
occur if the execution condition is not turned
ON or END(001) is not executed within the
maximum cycle time.
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
Program section A is executed
repeatedly as long as
execution condition a is OFF.