Mitsubishi STL programming

Does anyone has experience with Mitsubishi STL programming? I have a problem which I exemplify with the following example:

0 |-|m8002|-------------------[SET S0]-|
3 |-STL S0|----|^X0|--------[SET S20]-|
7 |-STL S20|---|^X1|-------[SET S21]-|
12 |-STL S21|---|^X1|-------[SET S22]-|
27 |-STL S22|-T-|^X2|-------------(S0]-|
32 | |--------------------[RET]-|
33 |---------------------------------[END]-|

where |^X0| is a LDP (LoaDPulse) instruction.

Turning the RUN/STOP switch to RUN, pressing button X0, program goes to state S20. Pressing X1 once, program goes directly to state S22. Pressing X2, program returns to state S0.
Pressing X1, program goes to S20, pressing X1 once, program goes to S21, pressing X1 again, program goes to S22, and so on.
In other words, in the first pass through the LD diagram, the first rising pulse of X1 activates both LDP succesive instructions (lines 7 and 12) - program goes directly to line 27, while on second and following passes, LDP succesive instructions are activated separately. The same goes if not only two, but many lines similar to line 7 and 12 are added.

Does anybody knows how to eliminate this different operation of the same diagram?

C.G.Haba

I have done some STL programming, and recognized that at power up, not all Steps are reset.
Try to reset all steps with command ZRST S1 S63 like this...
0 |-|m8002|--------|--------ZRST S1 S63]-|
.. . . . . . . . . . . . . .|-------------[SET S0]-|
8 |-STL S0|-|^X0|---------------[SET S20]-|


Stein

It is not the problem that some states are not reset at power-on (though I discovered this behaviour my self) because I have monitored the PLC operation and only S0 was active at the beginning. Is like that in the first pass through the stl diagram, load pulse ^x1 is not consumed in line 7 and therefore activates not only the transition from S20 to s21 but also the transition from S21 to S22 (and any number of succesive transitions triggered by a ^x1 condition).

cghaba

cghaba Is true, and no necessary PLS (pulse) it not adequade use in transitions STL.

Have you tried swapping line 7 and 12 around?

Swapping lines 7 and 12 makes no difference.

cghaba