Importance of Safety PLCs

Safety Programmable Logic Controllers (PLCs) are important because they are able to perform the same functions as standard PLCs but with additional features to ensure reliability and maintain safety through diagnostic capabilities and the capacity to initiate emergency shutdowns.

Are you new to the world of industrial automation and PLCs? Are you hoping to understand the basics of things like PLCs and major automation components in central California?

Keep reading to understand what a programmable logic controller (PLC) is and what the difference is between a safety PLC and a standard or conventional PLC. By the end, you’ll also understand why safety PLCs are important.

What is a Safety PLC?

A safety programmable logic controller (PLC) operates similarly to a standard PLC, but safety PLCs have additional features like integrated safety functions. Safety PLCs are considered more reliable than standard PLCs with additional hardware since safety PLCs have additional redundancies built-in.

Before safety PLCs were designed and added to automated processes, their safety functions were performed by memory designated toward safety instructions and hard-wired safety relays You may read more about the differences between Safety Relays and Safety PLCs in our article, Safety PLCs vs Safety Relays.

Programmable Logic Controller (PLC) Basics

A programmable logic controller (PLC) is a computer used in an industrial setting. These can be as small as a device with tens of inputs and outputs to a large, rack-mounted device with thousands of inputs and outputs. PLCs can communicate with other PLC systems or SCADA.

Programmable logic controllers (PLCs) dictate the manufacturing process to allow it to be automated. PLCs are important for managing the repetitive tasks in the process. They also make it possible to monitor and control industrial processes remotely.

Additional Features and Capabilities of Safety PLCs

A safety programmable logic controller (PLC) may be created by adding safety-rated hardware and functions to a conventional PLC. The newest Safety PLCs are designed and fully integrated with these safety components and functions from the beginning.

Safety PLCs Fail Safes

Safety programmable logic controllers (PLCs) are engineered and built not to fail. However, nothing is entirely perfect, so safety PLCs have built-in fail-safes to minimize danger and damage. A safety PLC’s fail-safe initiates a safe shutdown if failure is unavoidable.

Built-in Diagnostics

Safety PLCs contain the ability to diagnose failures by monitoring inputs and outputs. 


Safety programmable logic controllers (PLCs) have predictable failure modes to allow for rapid problem-solving and initiate safe shutdowns when necessary.

Limited Access

Safety PLCs can be locked and require a password to prevent someone from making changes to the safety programming without authorization.

Advantages of Safety PLCs

Your automation system may already contain PLCs with hardwired safety relays, but there are advantages to upgrading to a safety PLC instead. If you are still planning your initial automation system, there are even more advantages to using a safety PLC from the get-go.

Advantages of safety relays include

  • Less money and time are spent on wiring components for safety relay technology since the functions of safety relays are built into the safety PLC.
  • Safety PLCs within a system make the system more flexible and easier to change as needed because you can make programming changes instead of needing to add relays or change existing wiring.
  • The diagnostic information and functions from the safety PLC can easily be integrated into the other connected systems for the most efficient information tracking.
  • Prevention of unauthorized access to programming by password protection

Conclusion: Initial PLC Programming

Installing and integrating safety PLCs into your manufacturing processes can be daunting and complex. The good news is that many companies specialize in PLC programming services, so you can outsource this portion of the automation setup to get the best programming available.

Choosing the Right PLC Programming Services

Make sure you find a programming service that has a lot of experience in the automation industry. The initial setup and installation of a fully automated system is already expensive and complicated without setbacks from inexperienced programmers.

Access Industrial Automation has helped hundreds of manufacturing clients in and around Modesto and Stockton, CA, design, install, and program their automation systems.

Other services and benefits from Access Industrial Automation include

  • Custom PLC Programming: Your business has specific requirements and needs. That means that we will develop custom PLC programs to meet your objectives and integrate with any existing systems.
  • PLC System Integration: We integrate PLCs with other components in the system. These components may be sensors, Human Machine Interfaces (HMIs), actuators, and more. Whatever the system and components, we will help you obtain efficiency and cohesion. 
  • PLC Troubleshooting and Optimization: If you have problems with an existing PLC program, our experts will help diagnose and fix any issues. The improved performance and reliability will help you optimize your processes.
  • PLC Upgrades and Migration: Access Industrial Automation will help you update an older system with outdated PLCs or legacy systems to a modern, high-performance PLC platform.
  • Training and Support: We do more than just programming by offering training and support. Our comprehensive training programs will empower your staff with the knowledge and skills to operate and maintain PLC systems. We have a 24/7 dedicated support team.

Frequently Asked Questions

Do you need safety PLCs?

Manufacturing requires fail-safes, so you need a component, like a safety PLC, with predictable failure models to initiate safe emergency shutdowns. Without a safety PLC, you will need additional wiring and relays to perform this function. A safety PLC is considered more reliable than safety relays.

What does a safety PLC do?

Safety PLC detects and responds to hazards, errors, and faults in the manufacturing system. Responses include shutting down, initiating alarms, or transitioning to a safe state. Safety PLCs are more effective and reliable than using a standard PLC and additional hardware for these functions.

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