Advancements in PLC
Advancements in PLC
Introduction :-
PLC stands for Programmable Logic Controllers. They are basically used to control automated systems in industries. They are one of the most advanced and simplest forms of control systems which are now replacing hard-wired logic relays at a large scale, PLC, is a ruggedized computer used for industrial automation. These controllers can automate a specific process, machine function, or even an entire production line,
Need For PLC's
Hardwired panels were very time consuming to wire, debug and change., GM identified the following requirements for
computer controllers to replace hardwired panels.
- Solid-state not mechanical
- Easy to modify input and output devices
- Easily programmed and maintained by plant
electricians
- Be able to function in an industrial environment
- PLC is used in the fully automated industries or plants or process, the actual processes handled and controlled by the controllers which are nothing but the programming logic controllers that means PLC plays a very important role in automation section.
- PLCs constantly monitor the state of the systems through input devices and generate the control actions according to the logic given in the user program.
- It is a heart of control systems, PLC monitors the state of the system through field input devices, feedback signals and based on the feedback signal PLC determine the type of action to be carried out at field output devices.
- PLC provides easy and economic solution for many automation tasks like
- Operates control and monitoring.
- Co-ordination and communication.
- PID computing and control.
- Logic / sequence control.
Latest PLC Technology Trends
1) Compact size, Faster Processing Time and Cost Optimization
Technological improvements such as the shrinking size of processors, circuit boards, and other components; are greatly transforming the electronics industry. More so, these improvements are starting to impact PLCs, following the introduction of smaller PLCs in the micro and nano classes. Though smaller, these new PLCs are equipped with faster processors with improved cycle time, greater memory capacity, and new communication enhancements.
Previously, the aforementioned features were only a characteristic of higher-level and mid-range PLC systems, but in response to market demands, many of the higher-end features and functions are migrating to lower-end PLCs. This has led to a shift from larger PLCs to smaller ones, as even those in the micro and nano classers are capable of remote connectivity, Ethernet communication, onboard PID with auto-tune, motion control, and other control functions.
2) Improved Communications Network
In the last few decades, especially in the early 1990s, an excessive variety of communication protocols and networks have been developed for use in industrial communication. This trend continues to further focus on real-time communication technologies, raw and connectivity speed of Ethernet as well as other industrial control networks for a vast range of applications. In their present form, high-end PLCs include multiple ports to support several communication protocols. But looking into the future, this is likely to change as users continue to demand more standardized Ethernet and Wireless communication options. Even though it’s a wireless age, industrial processes would require more robust wireless technologies with enhanced data integrity and improved communication range, before we can witness a convergence of industrial and commercial wireless communication protocols.
3) PACs (Programmable Automation Controllers) and PLCs Merge
Generally, a Programmable Automation Controller (PAC) is a hardened modular industrial controller which uses a PC-based processor and it provides a variety of programming options beyond the IEC 61131-3 programming languages. It is also referred to as Industrial PC or just IPC. PACs are considered more advanced compared to PLCs. However, over the years, PLCs have continued to evolve while adapting improvements in hardware technology, software, and communications. With high-end features making their way into lower-end PLC processors.
4) The Open-Source PLC
Whenever we come across the term “open-source”, we think of a hardware design that is open source or a standardized non-proprietary PLC scripting language that should be implemented under a public license. However, the way the open-source era is influencing the PLC industry is quite comprehensive.
It is simply eliminating the idea of a PLC altogether, by suggesting that the PLC technology should be based on a computer system like Raspberry Pi. An increasing number of companies have taken up the Raspberry Pi and built it into a system that is rugged and can withstand extreme environments for industrial applications. In this case, a Raspberry Pi is typically paired with one or more circuit boards that provide the digital/analog and I/O features which make up a conventional PLC. With Raspberry Pi, the additional circuit boards are designed with the capability to withstand high currents and voltages and to provide the isolation required in an industrial environment. Therefore, in terms of hardware, the Raspberry Pi can at least be integrated into industrial automation through such extensions.
5) PLCs Designed for Industry 4.0
Many technological innovations like artificial intelligence, clouding computing, sophisticated sensors as well as big data analytics, have and continue to significantly impact the landscape of manufacturing industries. These industrial technological advancements are commonly referred to as Industry 4.0. In this new industrial reality, PLCs have continued to play a key role as the main control, input hub, and interface for human operators.
6) Unified Programming Environment
There has been a trend of combining Human Machine Interfaces (HMI), motion control and PLC into a unified programming environment. In the next several years, this trend is likely to continue. Following suit will be the integration of a PLC with an HMI processor on the same rack, and the inclusion of the monitor as an external option or as part of the package. This technology allows the configuration of either an HMI module or HMI processor with a PLC I/O rack.
7) More Power, Wider Data Sharing
PLCs are becoming more powerful, allowing them to be equipped with capabilities that earlier were only exclusive to the workstation and Personal Computer (PC) domain. This has translated to quicker and cheaper sharing of data from the PLCs situated on the factory floor, to the human operators at the Control Level. Some of the features that enable current PLCs to widely share data include Internal Relational Databases, FTP Servers, Web Servers, and sending E-mail.
Latest trends in industrial automation include increased use of analytics, growing use of PLCs, PACs, and increased cloud-based supervisory control and data acquisition (SCADA) systems. These trends will influence the industrial automation control market, according to a report. The report also predicts that these trends will also result in an eight percent compound annual growth rate (CAGR) for the Asia-Pacific region, but the trends are likely to be seen globally. Automation industry is moving towards a future of unparalleled productivity spurred by superior energy efficiency, better design and operator visualization, and rigorous safety standards.
Advancements:-
Fifty years ago, the Ladder Diagram (LD) replaced the hardwired relay logic as a PLC programming language. The LD language kept things simple for system engineers and designers who were used to relay logic, but at the time it had some limitations, particularly in terms of data handling and process control.
To address the challenges of ladder diagram, the IEC 61131-3 introduced other PLC programming languages such as Function Block Diagram (FBD), Structured Text (STX), Sequential Function Chart (SFC) and Instruction List (IL). However, developers of Ladder Diagram responded with its advancements which have surprisingly stayed relevant and powerful in programming industrial controllers. We could say all IEC languages have their strong points, like STX is well-suited for data manipulation. But Ladder Logic still forges on, and has remained a leader in terms of PLC programming languages by a wider margin.
For instance, control system suppliers and end-users support installation of a large base of equipment, machines and processes controlled by PLCs that are programmed in Ladder Diagram. Also, there’s a large group of maintenance personnel, electricians, technicians and engineers who prefer the simplicity of ladder logic programming technology. Moreover, regardless of the hardware used, the LD language has gone a long way in creating the industry standard for programming PLCs and this trend is likely to continue in the coming years.
1. Two-finger touchscreen
New touchscreen operation panels have the ability to recognize two fingers.
Although cell phones have had this feature for several years, this function is just being incorporated in industry, bringing with it great benefits:
- Allows you to zoom in the screens, mainly in graphics.
- ‘Shift’ functions with dual-key commands – ‘Ctrl + another key’, etc.
- Increases security in some operations.
2. Direct connectivity with SQL databases
Today the entire computer systems industry operates through databases. However, some years ago this data transfer to a PLC was not possible directly, so it was necessary to use an additional computer with a SCADA system to communicate with the databases.
- The new PLCs include connectivity, mainly with SQL (Structured Query Language).
- They are very easy to program, so it is not necessary to request support from IT staff in order to set them up.
- They allow us to have the information that interests us most for daily operation and process optimization.
- They save money and time in product development.
3. Robot control via PLCs
The modern components of these PLCs (chips, integrated circuits) give them extraordinary processing power.
- There is mid-range PLC equipment currently available that can handle up to 32 axes, which can be translated into the control of five robots with six axes each.
- There are dual ethernet ports to facilitate ring type topologies.
- Many screens already incorporate a web connection, so with a simple configuration we can access the robot's operation console from any mobile device.
4. Operator safety
They comply with SIL2 and SIL3 (Safety Integrity Level) for safety applications in machinery.
This makes it possible to guarantee that the risks posed by the equipment to people, the environment and machinery have been reduced to the lowest possible level.
Some four or five years ago there were very few companies that had this certification; however, today it is almost standard in PLCs.
- Reduces risk in everyday equipment operation for the worker.
- SIL-certified equipment has redundant (duplicated) CPUs that separate risk functions from ordinary ones.
- There are inputs and outputs capable of handling redundant channels according to the case.
- Programming with certified functions in emergency shutdowns, safety curtains, etc.
- Security with powerful encryptions that help prevent possible hacks.
5. ‘The time traveler’
This tells us what was happening in the system logic when an error occurred in the process. This is possible thanks to an integrated video camera with an internal recording of the actions in the PLC.
- Allows the user to ‘go back in time’ to reproduce the recording of the failed process and see what the PLC was doing at that instant.
- Makes fault analysis easier and helps find solutions quickly.
Latest PLC technology helps to monitor and control distributed server/multi user applications. It also provides a comprehensive and accurate picture of operations, meeting the demands of multiple stakeholders including maintenance, engineering, operations, and production information technology (IT). Reliable and robust functionalities can be obtained using the latest technologies of PLC. These technologies enable you to take advantage of visualization, mobility and other new technologies, meeting various challenges in process, discrete applications and delivering critical visibility when you need it.
New technology in industrial automation is the driver of progress for companies. From the conception to the introduction of the collaborative robots, we have seen a major change in the technological developments continuously shape the industrial automation landscape. These new technologies in automation industry will shape industry in the year ahead. However, global automation industry has been progressing and enhancing functionalities. Risk to security has enhanced interest in open-source software maintained by an active community eager to fix errors.
Future scope of industrial automation would be good enough as every technology is involved with automation techniques. It is the use of various control devices such as PC’s, DCs, and PLCs to control various operations of an industry without significant intervention from humans and to provide automatic control performance. In industries, there would be a set of technologies that are implemented to get the desired performance or output, making the automation systems most essential for industries. On the other hand, industrial automation involves usage of advanced control strategies such as cascade controls, control hardware devices and other instruments for sensing the control variables etc.
Conclusion:
Nowadays, most of the control system operation in industries used PLC as a controller to control the process. It contain in the process control, transportation, domestic appliances, production lines and so on. Using the PLC to control traffic light can reduce the used of hard-wired relays and other external components. PLC has an internal function such as timer and counter making it become sophisticated but simple in used. It also provides flexibility of control that based on the programming and can execute simple logic instruction which being used in ladder diagram. An Intelligent Traffic Light that used the PLC to control a cross-junction has been successfully developed. The PLC program (ladder logic diagram) for implement the three mode of traffic light operation; Normal Mode, emergency Mode and Night Mode, have been designed completely and can be operated effectively together with the model of emergency sensor (switch) for the Emergency mode and the IR sensor circuit that has been developed especially for the Night mode..
Blog By:
Raman Kulkarni
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