Best Practices for PLC Firmware and OS Updates

Programmable logic computers (PLCs) play an essential role in many modern-day industries, including most or all manufacturing and industrial sectors. Firmware and operating system updates keep PLCs running by fixing bugs and improving PLC performance.

Making safe, well-planned firmware and OS updates is important to ensure the functionality of the PLC. If you're a PLC technician, having the right training and information can help you complete successful PLC firmware and OS updates. Whether you're a student or an early-career PLC technician, these best practices can help.

What to Know About PLC Firmware and Operating Systems

System firmware is the code that operates on your PLC, while the operating system is the software that sits just above the firmware. Both firmware and operating systems need periodic updates to keep up with the changing needs of the many industries that use PLCs. Here are some of the reasons that PLCs require regular updates:

Bug fixes: Updates to PLCs can address communication bugs, hardware handling problems, scan cycle issues, and more.
Security patches: Security is a top priority in industrial operations. PLC security patches address security vulnerabilities as they arise.
Regulatory or safety requirements: Safety and regulatory compliance go hand in hand. As regulations change, PLCs must change as well.

Why Are Firmware and OS Updates Important?

Firmware updates help ensure system reliability. As hardware, software, and field devices change, so must the firmware and operating systems. Firmware and OS updates also help prevent unexpected behavior and system faults, and thus play an essential role in the long-term success of the PLC.

Before You Update, Make a Plan

The first step in updating your OS and firmware is to make a plan. Start by reviewing manufacturer release notes (the documents that detail the changes and enhancements). Release notes describe what changes were made, why the changes were made, and whether these changes produce any known issues. The release notes also detail which PLC models are supported.

Some PLCs must be kept operating at all times, while other PLCs have scheduled downtime for maintenance. As you plan the updates, it's important to determine whether your update must be performed while the PLC is running or during downtime.

Determine whether the updates are compatible with your PLC hardware, and identify the tools and access permissions required to make the update. Making this plan in advance helps ensure that your update will be successful.

PLC Firmware and OS Update Procedures

Every company and organization will have procedures for updates that are specific to the plant. Below is a general list of steps to take when performing PLC firmware and OS updates. As a PLC technician, you'll learn the steps for your company before performing any updates.

Step 1: Follow the pre-update checklist. Updates start with pre-update steps like backing up the PLC program and data and confirming power stability for the PLC.

Step 2: Execute. Follow the vendor-recommended update processes. Monitor status indicators as the update is taking place.

Step 3: Verify. Verify that the update has been a success by observing the system behavior. Be aware that updates can impact scan cycles, sometimes in very small ways. These small changes can impact various processes that affect the safety and functionality of the system. Running tests and observing processes is the only way to ensure that the update has been successful.

Version Control and Rollback Strategies

Sometimes updates put the security or safety of a system at risk. Have a rollback strategy in place, in case the firmware and OS update are unsuccessful. Maintaining firmware and program version records makes rollback much easier. Store backups securely to ensure a rollback can be performed efficiently if one is necessary.

Mitigating Risk During System Updates

There are many ways to mitigate risk during system updates.

Go through a risk assessment process before performing updates.
Have a plan in place for performing your update efficiently.
Have a plan for what to do if the update fails mid-process.
Engage in emergency response planning before performing updates. Update your emergency response plans periodically.
Use simulation and testing environments whenever possible to test an update before going live.

Common Mistakes to Avoid

These common mistakes can lead to failure when performing updates.

Skipping backups: Backups make rollback possible when an update fails. Never skip a backup to avoid data loss.
Ignoring vendor compatibility warnings: Some PLC systems are incompatible with some updates. Reading all available vendor documentation makes it possible to catch incompatibility before making an update that won't work.
Poor communication between operations and maintenance teams. Everyone involved in the operation of the PLCs should be aware of the update before it takes place. Maintaining good communication with the full operations and maintenance teams prevents mistakes and malfunctions.
Inadequate post-update testing: Test and observe your PLC after the update is over to ensure that the update has been successful.

Engage in Continuous Learning to Make Updates Easier

PLC technicians learn about the importance of continuous learning as part of their PLC Technician Training. Staying up to date with industry standards makes it easier to perform updates safely and effectively.

Get Started as a PLC Technician

Safety awareness and attention to detail are some of the core skills that every PLC technician should develop over time. Getting your PLC Technician Training from a trusted name in the industry can help you get off to the right start.

When you're ready to get started, call to learn more about George Brown Polytechnic's PLC Technician Training program. You can reach one of our Program Consultants at 1-888-553-5333 or by email at [email protected]