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PLC programming

Thread starter #1
I need help with a task that includes PLC programming in the software called Codesys. The task is to sort liquids with the help of valves etc. Could someone help me? I have trouble understanding it 100%. Further info will be given about the task.
Thread starter #3
Well, its mainly for ladder and function block if its what you meant. However, the task is like this:

a two color mixer must be controlled with PLS. The device works like this:

- When start switch S0 is operated, lamp H0 (refill) lights up. valve Y1 opens and pump M2 starts

- When sensor S1 is covered with liquid, valve Y1 closes and valve Y2 is opened.

- When sensor S2 is covered with liquid, close valve Y2, pump M2 and lamp H0 turn off and M1 starts

- After 6 seconds, M1 stops

- The unit can be switched off at any time with switch S6, thermal relays F1 or F2 (motor protection) or limit switch S4

- The ready-mixed liquid can then be manually withdrawn from the drain valve located at the bottom of the mixer

- The process can then start over again


Well-Known Member
I see, I much prefer the standard ladder logic rungs as it simulates the typical electrical schematic.
Most PLC's have some sort of Boolean blocks string type programming but I prefer the former.
The first thing is usually identify all inputs and outputs with a I/O address.
This is not homework/test by any chance?


New Member
Thread starter #6
I have completed 70-80% of the task, but Im stuck now, since its some things I dont understand. Do you mind helping me out?


New Member
Thread starter #8

So my questions are:
- Im not sure when I should reverse the signal.
- When to use SR/RS block
- And if H0 should me input or ouptut.



Well-Known Member
Without some review of the type of coding I cannot tell you, if it was ladder I probably could help easily.
You could try AAC if no one steps in, there is a few users there of Codesys.

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