Q5: When the user inserts a coin, the piston B is moved to the right through the command SB in order to release a can and the same for the piston A (command SA) in order to make a can available for the next user. Only one can is released for each coin inserted. The door of the output compartment is unblocked (command UNBLOCK), the user opens the door to pick the can, and then the door is blocked again (command BLOCK) after the user closes it. Create SFC chart based on action flow. Q5: When the user inserts a coin, the piston B is moved to the right through the command SB in order to release a can and the same for the piston A (command SA) in order to make a can available for the next user. Only one can is released for each coin inserted. The door of the output compartment is unblocked (command UNBLOCK), the user opens the door to pick the can, and then the door is blocked again (command BLOCK) after the user closes it. Create SFC chart based on action flow