PLC Advantages-Disadvantages, Diagrams, Different Languages.
- Advantages and disadvantages of PLC.
- PLC types based on input and output.
- PLC block diagram
- PLC internal structure
- PLC lists various brands.
- PLC programming language.
- Names of various SLCs PLCs, software, and cables used in the industry.
Preliminary ideas about PLC
The full meaning of PLC is the Programmable Logic Controller. PLC is a microprocessor Base Device with an Input / Output Card / Circuit. Inside which the program has to be programmed, the device after receiving an input after working logically on the previous program provides output according to the sequence.
The first PLC was invented by Modicon Company which is today known as Schneider Company whose name was Sequence Controller. In 1979 the model was 084, the scientist's name was Morley.
That's why Morley is called the mother of PLC. However, it did not find a market commercially. Then in 1973, Michael Greenberg invented the commercial PLC whose model was 184.
Advantages and disadvantages of PLC
Advantage
Based on input:
It is a 4 pin IC. It is a type of electronics component that transfers electrical signals from circuit to circuit using light. That is, it establishes electrical connections in two different circuits using light.
Based on the output:
It is the most widely used output. The relay is an electrically operated switch. This type of output can control both AC or DC. When working with PLC, it is often seen that there is a reference to 24VAC, 110VAC, or more Relay output.
Transistor type output
This type of output only switches to DC. This type of PLC biases the base of the transistor with a small amount of current.
Triac type output
Triac type output is used to control AC load only.
PLC block diagram
Input device
CPU or Central Processing Unit
This is basically the brain of PLC. Programs are provided in this CPU. An operator is programmed in such a way that he can control the output with the help of input switches.
Programming device
It is a device where programs are written, such as computers, laptops, etc.
Power supply
Most PLCs have 24 VDC or 220 VAC power supply.
Output
PLC internal structure
Output relay
This relay is used as output. This means that the output is switched with this relay. It can count from low to high or from high to low.
Counter
The counter is an English word which in Bengali means to count i.e. it will count the pulse.
There is also data storage through which data can be stored. There is a timer through which time can be counted.
PLC lists various brands
Besides, other brands of PLC are available in the market, but in the context of Bangladesh, Siemens, Delta, Mitsubishi brands are more used in Indra.
PLC programming language
The type of language used in PLC is:
Names of various Siemens series, software, and cables used in the industry.
Siemens PLC
Series: Logo
Series: S7-200
Series: S7-300 / 400
Series: S7-1200
Series: S7-1500
The full meaning of PLC is the Programmable Logic Controller. PLC is a microprocessor Base Device with an Input / Output Card / Circuit. Inside which the program has to be programmed, the device after receiving an input after working logically on the previous program provides output according to the sequence.
The first PLC was invented by Modicon Company which is today known as Schneider Company whose name was Sequence Controller. In 1979 the model was 084, the scientist's name was Morley.
That's why Morley is called the mother of PLC. However, it did not find a market commercially. Then in 1973, Michael Greenberg invented the commercial PLC whose model was 184.
Advantages and disadvantages of PLC
Advantage
- As it is small in size, it takes less space to control the industry.
- A plant's communication with a computer can be done.
- Saves energy.
- It is very easy to find problems in the case of technical people.
- Designing complex control systems costs relatively little.
- The work is much more perfect resulting in more production.
- It takes less manpower.
- The PLC program is relatively simple compared to other programs.
- It is very difficult for someone new to find out if there is a system or program error.
- Designing short and simple circuits is relatively expensive.
- Textile Industry
- Spinning
- Biomedical Industry
- Pharmaceutical
- Chemical
- Cement Factory
- Home Automation
- Food Factory
- Robots Manufacturing and controlling, etc.
Based on input:
It is a 4 pin IC. It is a type of electronics component that transfers electrical signals from circuit to circuit using light. That is, it establishes electrical connections in two different circuits using light.
Based on the output:
- Relay type output
- Transistor type output
- Triac type output
It is the most widely used output. The relay is an electrically operated switch. This type of output can control both AC or DC. When working with PLC, it is often seen that there is a reference to 24VAC, 110VAC, or more Relay output.
Transistor type output
This type of output only switches to DC. This type of PLC biases the base of the transistor with a small amount of current.
Triac type output
Triac type output is used to control AC load only.
PLC block diagram
Input device
- Selector or pushbutton switch
- Proximity sensor
- Transducer
- Analog sensors (RTD - Resistance Temperature Detector, Thermocouple), etc.
CPU or Central Processing Unit
This is basically the brain of PLC. Programs are provided in this CPU. An operator is programmed in such a way that he can control the output with the help of input switches.
Programming device
It is a device where programs are written, such as computers, laptops, etc.
Power supply
Most PLCs have 24 VDC or 220 VAC power supply.
Output
- Motor
- Heater
- Solenoid bulbs
- Lamps etc.
PLC internal structure
Output relay
This relay is used as output. This means that the output is switched with this relay. It can count from low to high or from high to low.
Counter
The counter is an English word which in Bengali means to count i.e. it will count the pulse.
There is also data storage through which data can be stored. There is a timer through which time can be counted.
PLC lists various brands
- Siemens PLC
- Delta PLC
- Mitsubishi PLC
- Allen Bradley (AB) PLC
- Omron PLC
- Schneider PLC
- Panasonic PLC
- Hitachi PLC
- Modicon PLC
- Fatek PLC
- Honeywell PLC
- Bosch PLC
- LS PLC
Besides, other brands of PLC are available in the market, but in the context of Bangladesh, Siemens, Delta, Mitsubishi brands are more used in Indra.
PLC programming language
The type of language used in PLC is:
- Ladder Diagram (LD)
- Function Block Diagram (FBD)
- Instruction List (IL)
- Structural Text (ST)
- Sequential Function Chart (SFC)
Names of various Siemens series, software, and cables used in the industry.
Siemens PLC
Series: Logo
- Model: OBA0-OBA8
- Software: Logo soft comfort
- Cable: Logo PLC cable
Series: S7-200
- Model: 200-299
- Software: Micro win
- Cable: PPI (Point to Point Interface)
Series: S7-300 / 400
- Model: 300-399 / 400-499
- Software: Simatic Manager
- Cable: MPI (Multipoint Interface)
Series: S7-1200
- Model: 1200-1299
- Software: Total Integrated Automation
- Cable: Local Area Network (LAN)
Series: S7-1500
- Model: 1500-1599
- Software: Total Integrated Automation
- Cable: Local Area Network (LAN)