A major component behind the efficient functioning of today’s process control systems is the programmable logic controller, or PLC. Uniquely suited to withstand tough industrial environments, PLCs serve to reliably automate many manufacturing systems, such as assembly lines or industrial equipment.
However, in certain applications, such as those involving machinery that poses a risk of operator injury, an additional layer of protection is required. That is where the safety PLC comes into play. This blog will discuss the general purpose of the safety PLC and its capabilities as well as its advantages over the standard PLC.
What is a Safety PLC?
A safety PLC is still capable of supporting all the key manufacturing applications that a standard PLC does. Its biggest difference, however, is that it also integrates safety functions that allow it to control key safety systems as well. The key objectives of safety PLCs are:
- Do not fail
- If failure is unavoidable, fail only in only the safest and most predictable way possible
The safety PLC meets these objectives by incorporating multiple redundant microprocessors. These built-in redundancy layers are a key capability because it means safety PLCs can eliminate the need for safety relays that are often used to create redundancy in the standard PLC. Safety PLC platforms include several standard diagnostic systems which enable them to continuously monitor inputs and outputs, searching for any potentially unsafe conditions. If these monitoring mechanisms detect an internal failure, a safe shutdown is initiated.
At its highest safety integrity level, a safety PLC is capable of detecting over 99% of potential system failures. This makes them suitable for use in applications that could cause harm to the employees, operators, environment, business, and equipment, including applications and installations that need to meet IEC 61511 and IEC 61508.
Safety PLCs vs Standard PLCs
Although similar to the standard PLC, a set of rigorous international standards must be met to be considered a safety PLC. The key to implementing PLC safety systems is to incorporate the best of PLC capabilities and integrate a safety controller into a single system.
The main benefit of standard PLCs is that they are simple to wire, easy to use, and do not require experienced technicians for troubleshooting purposes. This will generally make them more affordable; however, they typically have no way of detecting wiring errors on input/output (I/O), such as channel mismatches, ground faults, and short circuits. Different output types can lead to additional instability, and problems may tend to increase with an increase in the number of relay types. Delays in communication between components can lead to difficulties in diagnosis, which can be catastrophic in certain industrial applications.
Cost should never be the primary motivator when it comes to ensuring the safety of personnel, the business, the environment, and the community. Even though there are some additional costs associated with purchasing and maintaining safety PLCs because of their rigorous adherence to safety standards, the peace of mind, security, and benefits of these controllers definitely outweigh any cost concerns:
- Safety PLCs offer networking of input-output devices and diagnostics via human-machine interfaces. This can help to alleviate some installation costs.
- Robust diagnostics or information tracking capabilities are easily integrated and provide flexibility in many safety-essential applications.
- Financial and human resources can be minimized in field wiring, as safety PLCs serve to eliminate the need for safety relays.
- A safety PLC system is easy to modify as it only requires basic programming updates, without installing additional relays or necessitating any wiring changes.
Safety PLCs from Turner Integrated Systems
At Turner Integrated Systems, we are capable of designing safety PLCs for a wide range of applications that require extra protection. Located in Rochester, New York, we have in-depth experience in many PLC categories, and we custom-design systems to meet specific safety and operational requirements for each project. Contact us today for more information about our safety PLCs.
Operational networks can be vast for many industries. To carefully control and monitor the network within a facility, companies invest in a supervisory control and data acquisition system, or SCADA system.
Think of SCADA systems as industrial-grade real-time tools that incorporate multiple industrial control systems for optimal control and total supervision from a centralized system. The SCADA system allows for the live monitoring of real-time data across the entire network through a graphical interface. If detecting any anomalies, this system provides alarms and meaningful descriptions so workers know exactly what the issue is and where it is located to perform remediation. SCADA systems are built to be long-lasting and durable.
The key capability of a SCADA system is that it allows remote access to control equipment and systems. Workers don’t have to go to each individual equipment station to manually input or monitor functions. Instead, SCADA systems centralize the plant operations in one convenient location.
However, you may currently face problems with your SCADA control systems. Use these 7 reasons to learn about when it is time for new SCADA upgrades.
The Top 7 Reasons to Upgrade Your SCADA System
While OEM equipment may last for over a decade, facility owners may invest in newer technologies and systems to increase overall operational efficiency. Since these newer machines and equipment use updated technologies, the existing SCADA system may not fully integrate with the current technologies. Updating or replacing SCADA systems with new custom control systems ensures reliable connectivity to all systems.
Difficulty Using Current System
When your system operators try to interact with the current SCADA controls, older systems may function slowly or be difficult to use because they were not designed to complement the current equipment within the facility. This problem becomes further exacerbated when not having consistent Human-Machine Interface (HMI) design standards. This dashboard provides workers with greater monitoring and control of system functions throughout the facility.
Here at Turned Integrated Systems, our system manufacturing capabilities focus on providing high-performance HMI design standards for easier user control and more robust operations.
Poor Security Features
Since technology is constantly evolving, so are cybersecurity hacks and data breaches. Older SCADA systems simply do not have the newer security and encryption protocols in place to keep data from being mined, deleted, or held for ransom. New SCADA custom control systems have upgraded security protocols as well as two-step authentication, encryption, and secure remote access features.
Fewer Replacement Parts Available
As technologies evolve, fewer system manufacturers will stock older replacement parts for legacy SCADA systems. Your facility may have to go to the OEM to obtain the right parts, which could increase costs when sourcing materials. In time, even the OEM may start to phase out their replacement part inventories to only offer more current SCADA products and software.
Noncompliance with IT Standards
Companies constantly modify existing IT standards or institute new standards. The current SCADA system may no longer meet these standards, making a full upgrade or replacement of the system necessary. The IT standards may also change due to a previous data breach to shore up security gaps.
Unreliable Connectivity & Inconsistent Functions
Disparate system controls lead to various issues, including spotty connectivity during peak times of operation. Another issue involves trying to get the systems and equipment to perform optimally. Unfortunately, older SCADA systems can have inconsistent functions and capabilities, which can cause issues when trying to access and maintain systems across multiple facilities.
Lack of Newer Features/Functionality
Older SCADA features and functions may slow down operations. Your company may lose its competitive edge against rival companies that have newer SCADA systems. By upgrading your SCADA system, you can gain features such as access to 3D graphics, built-in reporting, forecasting, and even mobile support.
Custom Control Solutions from Turner
Experiencing any of the above issues may be indicators that it is time to either replace or upgrade your SCADA system. With a newer SCADA system, you can increase your competitive edge with greater operational efficiency and reduce redundant functions. Here at Turner Integrated Systems, we offer expert SCADA programming and industrial control designs for your specific operations. Contact our company to learn more.
Many modern industrial processes and equipment have significantly reduced their reliance on manual input. As more companies adopt automation within operations, production lines often incorporate advanced control systems.
A control system communicates the needs of the operator to the automated production equipment. As inputs get programmed, the control system facilitates the appropriate response from each device. The main function of the control system is to manage, control, monitor and regulate how the devices within its system respond to the received input to provide a controlled output.
Elements in a Control System
A variety of elements combine to form a control system. The primary components of a control system include:
Many industries rely on sensors to measure or monitor certain aspects of processes. The sensor may obtain measurements such as pressure, weight, speed, stress, and more. Sensors may monitor whether a function completes an assigned task to provide a desired output, such as allowing another control system to operate in the next part of the production line. Sensors often provide vital warnings when a system is malfunctioning.
Flow meters measure process fluids moving through pipes and systems and ensure that current conditioners do not exceed or fall short of their desired flow rates. These meters use various methods to measure factors such as the mass rate, linear/nonlinear rate, or volumetric rate of gases or liquids. The specific function depends on the type of meter used. The different types of meters include positive displacement, differential, and inferential meters.
A pressure sensor converts pressure within a system into a readable analog signal. Numerous process applications and hydraulic and pneumatic systems rely on pressure sensors to monitor relative system pressure. Examples of pressure sensors include pressure switches that trip at a specific pressure point, or pressure transmitters that offer differential analog or absolute pressure readings across a broad range of measurement.
Temperature detectors monitor the temperatures in the ambient environment, as well as in process fluids and materials. The control system may then quantify this data to perform a function, whether it involves moving a mechanical dial on a display, activating an alarm or notification, or more complex functions.
Feedback control systems are types of closed loop systems. In a closed loop system, the input may be at an undesired rate, volume, mass, temperature, or other factor. Rather than allowing an immediate output, an error signal tells the devices inside the control system to perform specific functions to bring the input to a preset level. The feed goes through the system repeatedly in a feedback loop until it reaches the correct level for output. The control system will only allow the input to proceed through the output when it reaches the specified level.
There are numerous design concepts that guide the development of industrial process control systems. Best practices for the control system design process include:
- Developing a thorough understanding of all goals for the system, including any variables that need to be controlled. Additionally, create a baseline set of specifications that you can use later to measure the performance of your control system.
- Next, develop a model of the process and how it should function. This will allow you to establish the configuration of the four main elements of any control system, which include controllers, actuators, amplifiers, and feedback components.
- Run simulations and analyze the performance of the control system. Continue to adjust and optimize the various parameters of your design and analyze performance until the control system meets your baseline specifications. Once these specifications have been met, you can finalize the design.
- With a finalized design, you can move into the programming and software development phase for your control system.
Control Systems by Turner Integrated Systems
Turner Integrated Systems provides industrial process control system design, software development, and fabrication services for manufacturers and industrial companies. We offer supervisory control and data acquisition (SCADA) systems and process control systems including flow meters, specialized sensor systems, analytical sensors, and remote access control systems. We offer simple control sensors for standalone equipment to highly advanced systems that may be linked to ERP systems or centralized analysis software.
For more information about control systems and how they can improve your production operation, please contact us today.