SCL command to Set output then make it off after some time

[ggg315]

How to make it happen In SCL

Code: Select all

IF (#CmdStart = 1) AND (#CmdStop = 0) AND (#Fault = 0) AND (#LockAct = 0)
       THEN
          #Start := 1;
          #Stop := 0;

How can I make this output be active for SOME TIME and then Vanish

if i can adjust this time it will be even better that i can do be defining a static value and using that in code

So it is to mimic the function of a pushbutton, this output will activate a relay and the relay contacts will close and open after some time same like a pushbutton

So I Need output and that should stop after x time

I dont want to use timer . this will be inside a 100ms OB

[MEFinc]

Why you don't want to use timers? It's the easiest way to solve your task.

[Dfcz]

Use the "set" and "reset".
The start command is set according to the conditions and the start command is reset according to the conditions that the start command is already seted.
Therefore, the start command will be seted 100 MS.

[ggg315]

Why you don't want to use timers? It's the easiest way to solve your task.

Because I think Timer can act in unpredictable manner.
https://www.dmcinfo.com/latest-thinking ... 200-timers

[Guille]

You can use the variable "OB1_PREV_CYCLE" and accumulate it on some static variable inside the FC and compare the accum. value with the time you want to reach (time in mili seconds)
You will need to add a function parameter on your FC where you can pass the OB1_PREV_CYCLE variable in the FC call

here you have a rudimentary example where you can see the accumulated time value (on Current_value)

https://support.industry.siemens.com/tf ... ageSize=10

you must analyze the overflow case to avoid problems

regards