Consider the above diagram, FIGURE, of the car park. The object of this assignment is to write a program to operate the barriers to allow the cars in and out.

As you can see there is a box in which there are two condition lights for when the car park is Full, and when there are Spaces.

The entrance to the car park is on the left hand side. When a car drives into the car park there is a sensor that detects the car and this should cause the barrier to be opened to allow the car in.

On the right hand side is the exit. When a car leaves the car park it will activate a sensor inside the park to open the exit barrier.

Both the entry and exit barriers will need to be in the Up position long enough to allow the cars to enter or leave the car park. The inputs and outputs are listed as follows:

IP0 = Entry Sensor OP0 = Entry Barrier
IP1 = Exit Sensor OP1 = Exit Barrier
OP2 = Full Light
OP3 = Spaces Light

When writing the program it is necessary to observe the following conditions. When the car park is not full the Spaces light should be ‘ON'. When the car park is full the Full light should be ‘ON'. As a car enters or leaves the car park the entry and exit barriers have to be held in the Up position long enough to allow the cars to pass under the barriers.

When the program is complete and the car park graphic is displayed in Simulation mode the program is operated by pointing at the car and clicking the mouse button. You will see directional pointers left and right so point at and click the direction you wish the car to travel. When you wish a car to leave the car park point at the one you wish to leave the park and click. You should explain the operation of the program, using the documentation facility.