You will develop a PLC system for a production line that produces containers with chemicals. There are two types of containers: One small of 1 liter and 1 large of 3 liters. Both types are made of metal.

The production line consists of the following stations:

The production line starts when an operator presses a Start button. The line stops using a Stop button.

Description of the Warehouse Station: Empty containers are stacked on top of each other in separate magazines, one magazine for large containers and one for small.

When small containers are to be produced, it is done according to the following procedure:

A cylinder pushes out one container from the magazine. The cylinder is then retracted. A traverse with a magnetic gripper picks up the container and places it on a conveyor belt belonging to the filling station. This is repeated 10 times before a new order can be started. Production of large containers follows the same procedure. If containers in a magazine are empty, an alarm light must come on. The traverse stops when it has delivered the container it was running and will not start again until the operator has filled new containers and acknowledged alarms.

Description of Filling Station: The filling station consists of a conveyor belt and a tank filled with chemicals. A regulator keeps the level in the tank constant. The regulator is not part of the task. The conveyor belt starts when an empty one arrives from the Storage Station and stops if no new containers arrive after a given time. When an empty container is placed on the conveyor belt, it is led to the filling point just below the tank. A cylinder makes sure to keep the container in place while filling. A valve at the outlet of the tank opens when the container must be filled. The amount to be filled is determined by the time the valve is open. It is a linear relationship between the time the valve is open and the amount of filling. When the container is full, it is transported on to the Lid Application Station.

Description of the Lid Fitting Station: The lid application station consists of a conveyor belt and a magazine with a lid. When a full container arrives from the Filling Station, the belt starts and transports the container to the position where the lid is to be put on. The belt stops and a clamping cylinder holds the container while the lid is pressed on. Once the lid is in place, loosen the clamping cylinder and move the container to the Storage Station. The lid is retrieved by an arm vacuum cleaner. The arm is a combination of a rotary cylinder and a linear cylinder. If the lid magazine become empty, shell an alarm light come on. No lids are put on until new lids have been placed in the magazine and the alarm has been acknowledged the operator.

Description of the Finished Goods Station: The finished goods station consists of a conveyor belt and a rotating table with space for 10 containers. When one finished container arrives at the end of the conveyor belt, it is lifted onto the table by a traverse with a gripper that clamps around the container. When the container is in place, the table is rotated to the next available one position. The position is determined by an incremental encoder connected to the motor shaft of the table. When 10 containers are placed on the table, all the containers are lifted off the table using a robot. The robot is not one part of the task.

Task

a) Make a simple sketch of the production line where you draw the necessary sensors and actuators. It is no need to determine sensor type or directional valve type (DCV). Describe assumptions and prerequisites

b) Create an I / O list based on the sketch and determine a PLC configuration with a sufficient number of digital I / O modules

c) Explain how you want to build up the PLC program (OB, FC, FB) so that you meet the requirements for structured programming and hardware independence. Also include initial states. Justify the choices you make.

d) Sketch the sequence for the Storage Station. Correct syntax and correct use of instructions are not needed here. Enter start mode.

e) Program the sequence for the traverse at the Finishing Station. Here you must use correct instructions. Enter the starting position for the traverse. Briefly explain how you want to program the positioning of the table

Storage Filling 7 LiD Fitting station Finished goods Station Istation