It should be a conveyer and there are three cylinders. Also “alguse andur” means starting sensor and “lõpu andur” means ending sensor. “töötab” means working and “ei tööta” means not working.
Translating these texts: Start - starting the system (constant 1). When system starts, status led will be on, process starts. Stop - it stops all the system (on anytime), all actuators will be in state “0”. Starting sensor - if the box is on a position, it will send “logic 1” and system will apply by the graph. Ending sensor - it reads how many boxes are finished (moved to the far right of the conveyer)