STL Programming

[cghaba]

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 cghaba@hotmail.com

[Sergei Troizky]

When the line 7 sets S21, the following line 12 reads it along with the pressed X1 pulse and sets S22 in the same scan. Put line 12 before line 7.

[cghaba]

It works the same when putting line 12 before line 7. C.G.Haba

[Sergei Troizky]

How is the button pulse formed? Does it have antiblinking timer? The button contact may blink and generate several pulses per pressing.

[cghaba]

I don't think is the button because this happens only on the first pass through the stl diagram (after powering the PLC or STOP-RUN operation) and not on the second, third or other succesive passes. cghaba

[Guest Fanakapan]

Mitsi STL programming takes a lot of studying and getting used to. It has some great points and some bad. The afore mentioned states still being active after power cycle. You have to learn to program interlocks between states (as standard practice) If you have the same input through 2 states you can get the dominoe effect (run through) but with an interlock, this is stopped. Try programming an interlock between the states (m relay) so that it is closed in the active state and open in the next state.