So is there a reason why the timer is always working, or does it depend on the used software? Moreover, is there a need for the Switch and IR Sensor inputs to be in the 2nd ladder, since the belt is enough to control the timer.

Moreover, I am not sure how can I add a memory to indicate that the timer has already ended, and the belt should start moving again (OR DONE with the IR Sensor?) Also, when I simulate, the timer keeps resetting and restarting itself, although video tutorials online showed that all timers stopped after they reached their preset time. I am not sure of the correctness of the diagram, however. After the 5s and the reset of the timer, I wish to have the belt start moving again (Note that at this stage the IR Sensor is still off), and the cycle is repeated. During the first second, 'Press' is also turned on. For the duration of 5s, 'ValveD' and 'ValveU' are both turned on.

Afterwards, the IR Sensor is activated, turning off the belt, and initiating the timer. The process I have in mind is as follows:Īs the switch is closed, the belt is activated.

I am doing a simple ladder diagram, and I came up with the following diagram: This is my second day of learning PLC online.