Upgrading legacy programmable logic controllers (PLCs) in industrial facilities can deliver major performance, reliability, and smart manufacturing capabilities. Is it time?

Warning Signs that It’s Time to Upgrade Your PLC Programmable Logic Controllers

Here is a checklist of some of the common warning signs that indicate it’s time to consider upgrading your programmable logic controllers (PLCs):

• Your current PLCs are obsolete or reaching end-of-life. The manufacturer may no longer support them with spare parts or software updates,
• PLCs lack sufficient memory or processing power for your application’s evolving needs. As you add capabilities or complexity, you find yourself hitting hardware limitations.
• You need capabilities that your legacy PLCs don’t support, like advanced communications protocols, integrated safety features, motion control, or higher-level programming languages.
• Proprietary programming software is still in use but outdated and no longer supported. New PLCs typically use more standard development environments.
• Your engineers have difficulty finding components, like I/O modules, that are compatible with your older PLC systems. Replacement parts may be discontinued.
• You are experiencing frequent failures of older PLC equipment. Repairs and troubleshooting require too much time and money.
• Data reporting, visualization, and analytics capabilities are limited. Newer PLCs offer superior networking, HMI integration, and connectivity to software platforms.
• You want to implement modern technologies like IoT, machine learning, or digital twins, but your current PLC infrastructure doesn’t support them.
• There are cybersecurity concerns, and your infrastructure does not incorporate the latest security protocols.
• You want to ensure your operation is futureproofed to make integration of emerging technologies easier and upgrade reliably.

Paying attention to factors like these can help you determine if PLC and automation systems modernization could contribute to the efficiency, capabilities, and productivity of your operation.

Conducting Cost-Benefit Analysis

Before you decide to upgrade your PLCs, you’ll need to perform a cost-benefit analysis to determine the value proposition that justifies the investment.

To do so, list the hard costs of the PLC upgrade, including expenses for new hardware, software, installation, testing, and training. Besides upfront costs, you want to consider the total cost of operations (TCO) including future maintenance. Then, examine the benefits and assign dollar values to improved performance, such as:

• Increased throughput and uptime
• Improved quality and reporting
• Reductions in scrap or rework
• Remote monitoring with automated controls
• Analytics and faster processing speeds

A cost-benefit analysis should analyze the opportunity cost of not upgrading your current PLCs. What opportunities are missed? What happens if you do not upgrade? For example, control systems for critical infrastructure and manufacturing have become popular targets for cybercriminals. The need for increased cybersecurity may justify the decision versus the downstream cost of a successful breach of your control systems.

Conducting diligent cost-benefit analyses ensures PLC upgrades deliver maximum ROI while avoiding missteps.

Considerations When Upgrading a PLC Programmable Logic Controller

There are several key areas you should take into consideration when thinking about PLC upgrades. You will want to clearly define the project requirements, timelines, and costs. It helps to solicit input from engineering and operators to set proper expectations.

Other considerations include:

Evaluating Compatibility with Existing Systems

Address potential compatibility issues between the upgraded PLC modes and existing input/output control cards and networks early on. Determine if legacy modules can be reused or require replacements, and factor those costs appropriately.

Minimizing Disruption to Operations or Production

Take the time to develop a risk management plan with contingency options in case of delays or malfunctions after upgrade implementation. Possibilities include temporarily reverting to legacy PLC systems, shifting production schedules to alternate lines, or pausing less critical processes.

Consider running upgraded PLCs in parallel during a testing period to ensure performance before switching.

Conducting Proper Training

Make sure to provide adequate time to train operators, managers, and maintenance personnel on any new PLC equipment before final deployment. Clear documentation and hands-on training are crucial for daily users to leverage upgraded capabilities. Failing to address this step can hinder adoption and result in frustration for staff, which can offset many of the performance gains.

Your Trusted Control System Integrator

Pacific Blue Engineering offers precision controls and data-driven solutions—providing custom automation, controls modernization, and functional safety devices for the most demanding projects.

For legacy migrations, PLC upgrades, and turnkey control system integration, Pacific Blue Engineering is your trusted control system integrator.

Is it time to upgrade your PLC programmable logic controllers? Contact the PLC expert at Pacific Blue Engineering today at (657) 201-8603 or request a consultation online to discuss your options.