Mitsubishi Electric melsec q00ujcpu User Manual page 202

Note that there may be a case where a device value will not be changed depending on the execution timing even
though the specified step is executed.
The following instructions need to be noted when registering executional conditioned device test settings.
• Instructions that do not change device values
A device value will not be changed by executing the excutional conditioned device test when the execution
timing has been set to "After executing instruction", specifying the step for instructions that do not execute
the next step, such as branch instructions.
*1: If the execution condition of an instruction is not satisfied, a device value will be changed based on the registration
data.
Table6.17 lists the instructions that do not change device values.
No. Classification
1 Stop
2
3 Jump
4
5 Repeat (Loop)
6
7
8 Subroutine program call
9
10
11 End
12 Jump
13 Return from subroutine program
14 Return from interrupt program
• FOR/NEXT instructions
When the executional conditioned device test setting is registered specifying the step for the FOR or NEXT
instruction, timing of device value change is different from the timing when steps for other instructions are
specified.
Table6.18 shows the device value change timing based on the execution timing.
Table6.18 Device value change timing when a step for the FOR or NEXT instruction is specified
Instruction of the specified step
FOR
NEXT
• END instruction
When the executional conditioned device test setting is registered specifying the step for the END
instruction, the execution timing is restricted to "Before executing instruction" only. If "After executing
instruction" is set, the CPU module returns a registration error to GX Developer.
*1
Table6.17 Instructions that do not change device values
Instruction
STOP
CJ
SCJ
GOEND
BREAK(P)
CALL(P)
FCALL(P)
ECALL(P)
EFCALL(P)
XCALL
FEND
JMP
RET
IRET
Before executing instruction
Executed once before the start of loop
processing.
Executed every loop processing.
(Executed after the operation of the
program between the FOR and NEXT
instructions.)
Operation
• When the execution condition for an instruction
is satisfied
A device value will not be changed even when
the specified step is executed.
• When execution condition for an instruction is
not satisfied
A device value will be changed after the
specified step is executed.
A device value will not be changed even when the
specified step is executed.
Execution timing setting
After executing instruction
Executed once after the start of loop
processing. (Executed before the operation
of the program between the FOR and NEXT
instructions.)
Executed once after the start of loop
processing.
CHAPTER6 FUNCTIONS
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