Directional Logic PLC -

How can you determine the direction of input by using stair pictures with PLC? Meaning, how can you save the situation?

Information of the previous state I need to set the direction that photobom has been activated .. forward or reverse if they are active in reverse, do one thing. If they are further active, take a different action. The input to be labeled from 1 to 6. The normal direction is 1 to 6.

The simple implementation of a link here is the ladder argument:

  | ----- [] ----- + ----------------- () ---- ---- | | Input | Output | | | | | ----- [] ----- '| Output  

and here's where you can reset the output:

  | ----- [] ---------- --- + --------- () -------- | | Input | Output | | | | | ----- [] ----- [/] ----- '| Output Reset  

These ladder logic create the original building block for memory. I'm not sure, but what are you looking for this?

Generally, the language implementing ladder logic will contain high level elements that apply memory such as D and T flip-flops

OK, by your comment it Looks like what you want:

  // pseudocode: // a = sensor1 // b = sensor 2 if (a) {a_triggered = true; } If (b) {if (! A_triggered) {REVERSE_DETECTED (); } And {a_triggered = false; }}  

It assumes that the sensors are nearly identical that the transition is 10-> 11-> 01, so that you can detect the travel direction, while triggering both the item sensor Be there Writing it declaratively:

  a_triggered = (a || a_triggered) & amp; Amp; ! (BTTrigger & amp; !! B); B_triggered = (B || B_TTiger) & amp; Amp; A_triggered; Reverse-bid = b & amp; ! A_triggered;  

Translation of:

  | ----- [] --------- + ----- [/] -------- () -------- | | One | C_trigid | | | | | ----- [] --------- '| | A_triggered | | | | ----- [] --------- + ----- [] -------- () -------- | | B A_trigitated B_trigger | | | | ----- [] --------- '| | B_tridgegeed | | | | ----- [] ---------- [/] ------------- () -------- | | BTTrigger BB | | | | ----- [] ---------- [/] ------------- () -------- | | B A_progressed reverse_dated.  

Now you can use the detected signal from the reverse to do whatever you want. If your ladder revolves around the language, then you can do this cleaner:

  | _________ | | ----- [] -------------------- | Set latch | ------ | | One | | | | ----- [] -------------------- | Clear | | C. _________ | | | A_triggered | | _________ | | ----- [] -------------------- | Set latch | ------ | | B | | | ----- [/] -------------------- | Clear | | A_triggered | _________ | | | B_tridgegeed | | | | ----- [] ---------- [/] ------------- () -------- | | BTTrigger BB | | | | ----- [] ---------- [/] ------------- () -------- | | B A_progressed reverse_dated.