Counting when sensor changes to false in SCL

[SamuVim]

Hi,

I have a sensor that is FALSE when it is triggered, and a setup with boxes running past the sensor.

I need to count how many boxes go past, is there a way to count +1 only when the sensor switches from TRUE to FALSE? I tried looking at rising edge default function and some suggestions on google, but can not figure it out. Which variables (and of what type) should I create to achieve this counter?

Thanks a lot!!

Samu

 

[JesperMP]

Something like this:

IF (NOT Sensor) AND Sensor_mem THEN
  Count := Count + 1 ;
END_IF ;
Sensor_mem := Sensor ;

N.B. Before anyone point out that I have added an 'unnecessary' parantesis, then I like to explicitly add parantheses that help visualize the logical order of the boolean formulas. I dislike it when something is implicit.

 

[SamuVim]

Thanks for the super quick reply, works now!

 

[drbitboy]

...I dislike it when something is implicit.

+1e6; no complaint here; I work in too many languages to bother wasting neurons memorizing the precedence rules for each one.



We could reverse the order of the tests, then there is nothing implicit (I think).