I. Design Problem You are requested to design a PLC program for a five floors smart elevator system. The system has the following specifications: The design must be simulated on the Siemens LOGO software. It has 5 floors: Ground floor (Floor 0), floor 1,2,3 and 4 It is made up of two DC motors: A motor (M1) that takes care of moving the elevator up or down A motor (M2) that takes care of the opening and closing of the elevator door The DC motors (M1 and M2) are wired in the forward-reverse configuration in such a way that: Moving forward corresponds to moving up of the elevator for M1 and closing of the elevator door for M2. Moving in reverse direction corresponds to moving down of the elevator for M2 and opening of the elevator door for M2. Keep in mind that you need two PLC output control pins per motor in order to control the polarity of voltage as applied to the DC motor such as it can go forward in one case and reverse in the other case. The elevator also uses 5 different types of position sensors (level sensors) (S0, S1, S2, S3 and S4)with the purpose to detect that the elevator has reached a specific floor. Consider that when each sensor is triggered, its output produces a LOW level logic output. This means that when not triggered, the sensors output logic is a HIGH-level. The elevator also has 5 command buttons (B0, B1, B2, B3, B4). It is one button for each floor. Consider that these are normally opened push buttons configured in normally LOW mode Only one button can be pressed at a time When a specific button is pressed, the motor M1 must either run forward (going up) or downward (going down) depending on whether the button pressed corresponds to a floor higher or lower than the floor on which the elevator is currently located at. The motor runs forward or reverse up until, the motor reaches the selected floor which you will detect by the sensors of that specific floor being triggered. When you reach the selected floor, the doors remain closed for 2 seconds before they open to let people going down on that floor. The opening and closing of doors take up to 10 seconds. This means M2 must be run for 10 seconds for closing and for 10 seconds for opening the elevator door. After the door has opened, it can either close if someone presses another button for another floor or if a waiting delay of 3 seconds elapses after the door was opened. The system also has a temperature sensor (T) that is used to detect the rise of temperature due to abroken fan (cooler) (F). We will use a SPDT switch to simulate the breaking and fixing of the fan(cooler). When the fan (F) is broken (F= 1), we will set T (T= 1) to show that temperature has risen above a comfortable threshold temperature value. Similarly, when the fan (F) is fixed (F= 0, we will clear the temperature sensor T (T= 0) to indicate the temperature in the elevator has fallen below the minimum threshold temperature. Whenever the temperature in the elevator has risen above a certain temperature, the elevator must go down (M1 turning in reverse) to the Ground floor (Floor 0) and once it reaches the ground floor it must open the doors (M2 turning in reverse). to allow for cool air to enter the elevator. Taking someone to the ground floor is implemented as running M1 in reverse in terms of 5 seconds per floor. For example: If by the time the fan is broken and T detected rising of the temperature you are on floo2 2 (3rd floor), M1 should run in reverse for 5 seconds * 10=10 seconds to show that we reach the ground floor. This is dynamic, meaning if we are from floor 3 (4th floor), it will be 15 seconds etc. When the elevator reaches ground floor, this is detected by the appropriate number of seconds elapsing while M1 is running in reverse but also by S0 triggering to say that we are now on ground floor. Of course, you know that each time you reach a floor, M1 must stop running, 2 seconds later, doors open etc. However, in this specific case of reaching ground floor because the fan was broken, the following should happen: The elevator also has an Alarm buzzer device (B) and an alarm light (L) which ring (for A) and switch On (for L) when they receive a logic 0 and stops ringing (for A) and switches OFF (For L) when they receive a logic 1. The alarm rings when the temperature T is detected to have risen (meaning when the fan is broken) and for all the time that we are going down to the ground floor. When you reach the ground floor, 2 seconds later, the door should open but 3 seconds after opening it should not close like usual for as long as the fan is not fixed. When the door opens, the alarm buzzer (A) should stop ringing but the alarm light should only go off if we have reached the ground floor, the door has opened and on top of that, the fan has been fixed. The elevator also has a 7-segment display (common-anode) which indicates the floor on which wejust arrived. This means it displays a value of 0,1,2,3 or 4 once we reach the ground, floor 1, 2, 3or 4 respectively. The 7 segment display lights up before the door opens and goes off once M1 startrunning again to go to a new floor. In the case of a broken fan scenario, after we have reached theground floor, the 7-segment display remains ON showing the value of 0 till the fan is fixed.