162
(c) Execution timing
Timing to change a device value can be specified. A device value can be changed either before or after an
instruction of the specified step is executed. The following figure shows the module operation based on the
execution timing.
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
*1
A device value will not be changed by executing the executional 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.
<Program example>
Ladder mode List mode
<Operation>
Execution timing CPU module operation
Before executing
an instruction of
step 101
After executing
an instruction
of step 101
Processing
LD M0
10 20 120
Changes the value in D0 to "20".
+ K100 D0
Value in D0
Processing
LD M0
10 110 20
Changes the value in D0 to "20".
+ K100 D0
Value in D0
Executional conditioned device test which
sets "20" in D0 in this step is registered.
To Next Page
Loading...
