Q1. Identify and select a mechatronic system (non plc base) around you, then inv
ID: 2293597 • Letter: Q
Question
Q1. Identify and select a mechatronic system (non plc base) around you, then investigate the parts of the system and their technical specifications those are related to the key-elements of the mechatronic system (type of controller, sensors, actuators, etc). Explain in brief its principle operation, too CLO1 (40 marks) Q2. Investigate the possibility to modify the system on Q1 to be controlled using PLC. Select any PLC you know, modify the sensors, actuators, etc. to be matched to implement to the PLC, then design/skecth VO wiring diagram of the modified system. CLO2 (60 marks)Explanation / Answer
Programmable Logic Devices (PLD) are programmable systems and are generally used in manufacturing automation to perform different control functions, according to the programs written in its memory, using low level languages of commands. There are following three types of PLDs are being employed in mechatronics systems.
Microprocessor
It is a digital integrated circuit which carries out necessary digital functions to process the information obtained from measurement system.
Microcomputer
It uses microprocessor as its central processing unit and contains all functions of a computer.
Programmable Logic Controller (PLC)
A typical programmable machine has basic three components as shown in Figure 3.1.1:
Processor, which processes the information collected from measurement system and takes logical decisions based on the information. Then it sends this information to actuators or output devices.
Memory, it stores
the input data collected from sensors
the programs to process the information and to take necessary decisions or actions. Program is a set of instructions written for the processor to perform a task. A group of programs is called software .
Input/output devices : these are used to communicate with the outside world/operator.
Microprocessor
It is a multi-purpose, programmable device that reads binary instructions from a storage device called memory, processes the data according to the instructions, and then provides results as output. In common practice it is also known as CPU (central processing unit). CPU can be referred as complete computational engine on a single chip. First Microcontroller, Intel 4004 was launched in 1971. It was able to process just 4 bits. It started a new era in electronics engineering. Microprocessor chip was one of the important inventions of the 20th century. Table 3.1.1 shows the history of micro-processors.
Applications of microprocessors are classified primarily in two categories:
Reprogrammable Systems : Micro computers }
Embedded Systems : photocopying machine, Digital camera
Microprocessor works or operates in binary digits i.e. 0 and 1, bits. These bits are nothing but electrical voltages in the machine, generally 0 - low voltage level, and 1 - high voltage level. A group of bits form a ‘word'. In general, the word length is about 8 bits. This is called as a ‘byte'. A word with a length of 4 bits is called as a ‘Nibble'.
Functions of microprocessor
Various functions of m icroprocessor are as follows:
Microprocessor performs a variety of logical and mathematical operations using its ALU.
It controls data flow in a system and hence can transfer data from one location to another based on the instructions given to it.
A microprocessor can take necessary decisions and jump to a new set of instructions based on those decisions.
2.2 Elements of microprocessor
A simple microprocessor consists of following basic elements (see Figure 3.1.3):
Data Bus: Through data bus, the data flow between
various storage units
ALU and memory units
Address Bus: It controls the flow of memory addresses between ALU and memory unit.
RD (read) and WR (write) lines set or obtain the addressed locations in the memory.
Clock line transfers the clock pulse sequence to the processor.
Reset Line is used to restart execution and reset the processor to zero.
Address Latch is a register which stores the addresses in the memory.
Program Counter: It is a register which can increment its value by 1 and keeps the record of number of instructions executed. It can be set to zero when instructed.
Test Register: It is a register which stores intermediate or in-process data of ALU operations. For example it is required to hold the ‘carry' while ALU is performing ‘addition' operation. It also stores the data which can be accessed by Instruction decoder to make any decision.
3-State Buffers: These are tri-state buffers. A tri-state buffer can go to a third state in addition to the states of 1 and 0.
The instruction register and instruction decoder are responsible for controlling the operations of all other components of a microprocessor.
There are following control lines present in a microprocessor, which are used to communicate instructions and data with the instruction decoder.
Instruct the A register to latch the value currently on the data bus.
Instruct the B register to latch the value currently on the data bus.
Instruct the C register to latch the value currently output by the ALU.
Instruct the program counter register to latch the value currently on the data bus.
Instruct the address register to latch the value currently on the data bus.
Instruct the instruction register to latch the value currently on the data bus.
Instruct the program counter to increment.
Instruct the program counter to reset to zero.
Activate any of the six tri-state buffers (six separate lines).
Instruct the ALU what operation to perform.
Instruct the test register to latch the ALU's test bits.
Activate the RD line.
Activate the WR line.
Microcomputer
Microcomputer is a microprocessor based system. It is a data processing system that employs a microprocessor as its central unit. Based on the input it takes decisions. These decisions are further used to control a system or to actuate an action or operation.
It is a microprocessor-based system. It implements the functions of a computer and a controller on a single chip. Generally microcontroller is programmed for one specific application and it is d edicated to a specific control function.
Microcontrollers find applications in automobiles, aircraft, medical electronics and home appliances. They are small in size and can be embedded in an electromechanical system without taking up much space. Thus we can have a system with its functions completely designed into a chip. However microcontrollers have very little user programmable memory. Various types of microcontroller chips available in market are: Motorola 68HC11, Zilog Z8 and Intel MCS51 and 96 series.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.