Benefits of plug-and-play PLC migration

Manufacturers need programmable logic controllers (PLCs) to be interconnected and enable seamless data exchange and remote input/output (I/O) monitoring.

By Weidmüller October 12, 2023
Courtesy: Weidmuller

PLC migration insights

  • Aging programmable logic controller (PLC) systems risk obsolescence, hampering critical updates and data exchange. Neglecting migration jeopardizes productivity, reliability and competitiveness.
  • Compared to rip-and-replace, plug-and-play migration minimizes downtime, ensures accuracy and allows flexibility in brand transitions, enhancing reliability and profitability.

Amidst the continuous evolution in industrial automation, the need to upgrade maturing Programmable logic controllers (PLCs) stands at a pivotal crossroads of challenge and potential. As industries advance, the dependence on antiquated frameworks that are deficient in crucial functionalities, security measures, and networking proficiencies, has grown increasingly unsustainable.

The urgency for PLC migration

The catalyst for migrating from legacy PLCs arises from their obsolescence and declining level of support. These aging systems are approaching a point where they will deprive industries of critical software updates, firmware advancements, and factory support. The absence of networking capabilities in legacy PLCs also restricts communication between controllers and hinders data sharing across a plant. Modern industrial needs require PLCs to be interconnected, enabling seamless data exchange and remote input/output (I/O) monitoring.

The emergence of remote I/O systems empowers localized monitoring and control while facilitating network-based reporting. Where traditional PLCs lack the necessary functionalities to integrate with remote I/O systems, the newer generation of PLCs excels in this aspect. This shift from isolated systems to interconnected networks enhances efficiency, productivity, and data-driven decision-making.

Photo 1: The MiBridge migration solutions from Weidmuller cover a wide range of existing legacy programmable logic controller (PLC) platforms and can seamlessly integrate a plug-and-play migration across various brands. Courtesy: Weidmuller

Photo 1: The MiBridge migration solutions from Weidmuller cover a wide range of existing legacy programmable logic controller (PLC) platforms and can seamlessly integrate a plug-and-play migration across various brands. Courtesy: Weidmuller

Migration opportunities hold universal applicability, given that PLCs are used across many industries.

“Petrochemicals, oil, gas, food and beverage, pulp and paper, steel — there’s not a machine in the world that doesn’t have a PLC, or a controller of some type. So, there’s really no industry that’s not affected by this,” said Bill Conn, director of process industry sales at Weidmuller USA. The escalating consumer demand reinforces the necessity for migration as it emphasizes the paramount importance of increasing production efficiency.

The ramifications of neglecting migration are severe. As aging systems inevitably cease to function due to the scarcity of replacement parts and the fading of technical support, the issue of security compounds the concern.

“A lot of the antiquated systems are not secure and pose a risk of being infiltrated. As a result, migration becomes a top consideration when plant supervisors and industry leaders assess their risks and strategies for risk mitigation,” said Andrew Phillips, product manager, PLC migration solutions at Weidmuller USA.

These concerns place productivity, reliability and competitiveness in jeopardy. As technological improvements progress, the reliance on temporary fixes or band-aid solutions is purely unsustainable.

Photo 2: PLC or distributed control system (DCS) migration with Weidmuller’s MiBridge migration interfaces does not require any additional space in the control cabinet. The rack system takes the place of the old controller and combines the connection level and the new controller into one compact unit. Courtesy: Weidmuller

Photo 2: PLC or distributed control system (DCS) migration with Weidmuller’s MiBridge migration interfaces does not require any additional space in the control cabinet. The rack system takes the place of the old controller and combines the connection level and the new controller into one compact unit. Courtesy: Weidmuller

Choosing between rip-and-replace or plug-and-play migrations

While rip-and-replace has long been the go-to for PLC upgrades, delving into the drawbacks it presents compared to plug-and-play solutions reveals the apparent benefits that come with embracing a more contemporary PLC migration strategy.

Disadvantages of rip-and-replace include:

  • Expensive

  • Time-consuming

  • High potential for I/O wiring errors, consequently causing delays

  • Extended operation downtime during installation.

Advantages of plug-and-play include:

  • Limited downtime, which leads to a faster operation restart and cost-savings

  • The ability to migrate from one brand to another brand

  • Cables are prechecked for 100% accuracy

  • Utilizing the existing footprint eliminates the need for cabinet drilling

  • Field wiring remains undisturbed, mitigating the need for troubleshooting and minimizing risks.

Attempting a rip-and-replace strategy, for example, during a scheduled shutdown can lead to unforeseen challenges. In such instances, the process of removing the old system might uncover unexpected elements or issues that were previously unknown. This discovery of unforeseen complications could require adjustments, prolonging the shutdown duration. Furthermore, the installation process for rip-and-replace typically demands at least twice the time.

Conn said, “Especially with a large system, there are hundreds and possibly thousands of connection points to be made for all inputs and outputs. So, with a large system, rip-and-replace can be quite expensive and extremely time-consuming. Additionally, and probably the most vital aspect, is accuracy of the connections. If you misplace one wire during the rip-and-replace, say it should have gone to Terminal A, but it’s put on Terminal B, when you turn the system on, it could be detrimental.”

In contrast, through plug-and-play, the configurations are meticulously quality-controlled. If a connection is designated to travel from Terminal A to Terminal X, it is guaranteed to follow that route. This precision eliminates any potential deviations or complications. Plug-and-play also streamlines the transition by starting with a pre-qualification of connections through an analysis of both the current and incoming systems, effectively eradicating unexpected issues.

Further, installation time for plants is significantly expedited through plug-and-play. Phillips recalls a facility that converted fourteen 16-slot racks in only five days, which would have required 10 to 15 days with rip-and-replace.

Expanding on its benefits, advanced plug-and-play solutions can extend beyond the boundaries of specific brands. For instance, if a facility desires to transition from brand A to brand B, advanced plug-and-play solutions can be tailor-made to accommodate this, offering unprecedented flexibility for industrial plants. Thus, plug-and-play not only reduces downtime but simultaneously mitigates risk, enhances reliability, and maximizes profits by getting plants restarted and operational sooner.

Technical process of plug-and-play PLC migration

Embarking on the plug-and-play journey, plant leaders start the process by completing a detailed migration planning workbook. This hands-on step becomes the guide as it provides a holistic understanding of the unique needs of each plant. With these insights, product managers formulate the optimal solution tailored to each plant’s individual requirements and the process advances to custom “engineered” drawings, including engineered custom cable lengths.

This level of specialization helps ensure a successful migration and lays a solid foundation for ongoing success. While most solutions are tailored to individual plants, there also exists an extensive catalog of verified solutions that can expedite the delivery process even further.

The actual installation begins by disconnecting terminal blocks or a switch arm from the old PLC, a step that ensures wiring to sensors and actuators remains intact, eliminating the need for extensive field cabling interventions. The old rack is then extracted, making way for the new without disturbing the existing wiring layout. The migration process continues with the assembly or mounting of the new rack in the same space occupied by the old one, saving valuable real estate.

The corresponding adapter is installed, serving as a bridge between the old and new systems. The migration process retains the existing field signal by connecting the swing arm to the adapter and incorporating an auxiliary cable to the new PLC. This simplicity in design translates to maximum migration efficiency, allowing electricians to focus on the upgrade itself rather than being consumed with intricate wiring arrangements.

A standout feature of this solution is its minimalistic components, including versatile card adapters and cables. The migration interface is crafted to fit within the existing control cabinet space, eliminating the need for extra space allocation. This ensures the new controller integrates into the existing infrastructure.

Envisioning the future of industrial migration

PLC migration is emerging as a high-priority Industry 4.0 initiative, and all industry sectors will allocate significant financial resources to upgrade their legacy systems. The economic advantages of enhanced security, productivity, efficiency, and sustainability are driving serious manufacturers to opt for smart and sophisticated migration solutions.

The accelerating pace of technological advancements further underscores the necessity of adaptable systems that can evolve with the times. The migration from legacy PLCs to advanced solutions with networking capabilities is a pivotal step toward securing the future of industrial automation.

– Edited by Chris Vavra, web content manager, CFE Media and Technology, cvavra@cfemedia.com.