Securely Connecting to Siemens PLCs with Industrial VPNs


Imagine the power of remotely monitoring and managing your Siemens PLCs from anywhere in the world. Industrial VPNs (Virtual Private Networks) make this a reality, allowing secure and reliable access to your critical automation systems. This guide delves into the world of industrial VPNs, specifically focusing on their application for remote connections to Siemens PLCs.

The Rise of Remote Monitoring: In today’s globalized world, industrial automation is no longer confined to a single location. With manufacturing facilities spread across continents, the need for real-time data monitoring, troubleshooting, and remote maintenance has become paramount. Remote access allows engineers to keep an eye on operations, diagnose issues, and even perform maintenance tasks without being physically present. This not only saves time but also significantly reduces downtime, leading to increased efficiency and productivity.

The Challenge of Security: However, with great power comes great responsibility. Industrial control systems are highly vulnerable to cyberattacks. Unlike standard consumer VPNs, which might offer basic security, industrial environments require robust, specialized solutions to protect sensitive data and maintain operational integrity. In the face of rising cyber threats, ensuring secure communication channels is more critical than ever.

Introducing Industrial VPNs: Built for Secure Connectivity

Beyond Consumer VPNs: Let’s face it, consumer VPNs are great for hiding your browsing habits from prying eyes or accessing geo-blocked content, but they just don’t cut it for industrial applications. Industrial VPNs are designed with the specific needs of industrial automation systems in mind. They provide robust security features, including strong encryption, user authentication, and access control mechanisms, to safeguard sensitive industrial data.

Key Features of Industrial VPNs:

  • Strong Encryption Protocols: Industrial VPNs typically use encryption standards such as AES-256 or higher to ensure that data transmissions are secure and cannot be intercepted or tampered with.
  • User Authentication and Access Control: To prevent unauthorized access, industrial VPNs implement strict user authentication processes. This often involves multi-factor authentication (MFA) to add an extra layer of security.
  • Secure Tunneling Protocols: These protocols create a secure virtual connection over a public network like the internet. Common tunneling protocols include OpenVPN and IPsec.
  • Network Segmentation: This feature isolates industrial control systems from other networks, reducing the risk of cyberattacks spreading across different systems.

The Siemens Advantage: Leveraging Native VPN Support

Seamless Integration: Siemens PLCs stand out in the market due to their built-in VPN functionality. This means that many Siemens PLCs come pre-equipped with the capability to establish secure remote connections without the need for additional hardware or complex configurations. This seamless integration significantly simplifies the process of setting up secure remote access.

Popular VPN Options for Siemens PLCs: Siemens PLCs support various VPN protocols, with OpenVPN and IPsec being among the most popular:

  • OpenVPN: An open-source protocol known for its strong security and flexibility. It allows for a high degree of customization, making it suitable for a wide range of industrial applications.
  • IPsec: A well-established protocol that provides robust security features. While it may require additional configuration, it offers a high level of security and is widely used in industrial environments.

Setting Up Your Secure Connection: A Step-by-Step Guide

Gathering Requirements: Before diving into the configuration process, it’s crucial to identify the specific requirements for setting up a secure connection:

  1. Identify the Siemens PLC Model: Determine the specific model of Siemens PLC you are using and check its VPN capabilities.
  2. Choose a Compatible VPN Client: Select a compatible industrial VPN client software or hardware solution based on your specific needs.
  3. Define User Access Levels: Establish user access levels and authentication methods to ensure that only authorized personnel can access the system.

Configuration Steps: While the exact configuration details may vary depending on the chosen solution, the following high-level steps outline the general process:

  1. Configuring the Siemens PLC VPN Settings: Use dedicated Siemens software tools to configure the VPN settings on the PLC.
  2. Setting Up the VPN Client: Install and configure the industrial VPN client software on your remote device.
  3. Establishing Secure Connections: Use user authentication and authorization methods to establish secure connections between the Siemens PLC and the remote device.

Testing and Verification: Once the configuration is complete, it’s essential to thoroughly test the connection to ensure everything is working correctly. This includes:

  • Testing Secure Communication: Verify that secure communication is established between the Siemens PLC and the remote device.
  • User Authentication: Ensure that the user authentication and access control mechanisms are functioning as intended.

Choosing the Right Solution: Industrial VPN Options

Software vs. Hardware VPN Clients: When it comes to selecting a VPN client, you have two main options: software VPN clients and hardware VPN clients.

  • Software VPN Clients: These offer flexibility and cost-effectiveness, but may require additional IT expertise for configuration. They are ideal for environments where scalability and customization are key considerations.
  • Hardware VPN Clients: These provide dedicated security appliances with user-friendly interfaces, potentially making them easier to set up. However, they might come with higher costs.

Popular Industrial VPN Solutions: There are several prominent industrial VPN solutions available on the market. Some of the well-known vendors include:

  • Cisco AnyConnect: Cisco’s AnyConnect is a widely used VPN solution that offers secure remote access, endpoint protection, and identity services. It’s suitable for both enterprise and industrial environments.
  • Rockwell Automation FactoryTalk®: Designed specifically for industrial automation, FactoryTalk® provides secure connectivity for Rockwell Automation devices and systems. It ensures data integrity and confidentiality.
  • Siemens Scalance: Siemens offers Scalance VPN routers and firewalls for industrial applications. They provide secure communication between different plant areas, remote sites, and mobile users.
  • Phoenix Contact mGuard: The mGuard series by Phoenix Contact includes industrial firewalls and VPN routers. These devices protect against cyber threats and allow secure remote access.
  • Hirschmann Secure Remote Access: Hirschmann’s industrial VPN solutions focus on secure remote maintenance and monitoring. They are suitable for critical infrastructure and automation systems.

Beyond the Basics: Advanced Considerations (Optional)

Firewall Configuration: Configuring firewalls on both sides of the connection is crucial for maintaining network security. This involves:

  • Restricting Access: Limit access to authorized users and specific ports to reduce the risk of unauthorized access.
  • Monitoring Traffic: Regularly monitor network traffic to detect and respond to potential threats.

Multi-Factor Authentication: Adding an extra layer of security beyond usernames and passwords can significantly enhance the security of your industrial VPN. This can include:

  • One-Time Codes: Use one-time codes sent to a user’s mobile device or email.
  • Biometric Authentication: Implement biometric authentication methods such as fingerprint or facial recognition.

Remote Monitoring and Management Platforms: Industrial VPNs can facilitate secure access for remote monitoring and management platforms, allowing for:

  • Real-Time Data Visualization: Access real-time data from remote locations.
  • Remote Control: Perform remote control and troubleshooting tasks without being physically present.

Conclusion: Empowering Remote Access with Security

Recap the Advantages: Industrial VPNs provide a secure and efficient way to remotely monitor and manage Siemens PLCs. They offer several key benefits, including:

  • Remote Monitoring: Enables real-time monitoring of industrial processes from anywhere in the world.
  • Troubleshooting and Maintenance: Facilitates remote troubleshooting and maintenance, reducing downtime and improving efficiency.
  • Secure Access: Provides robust security features to protect sensitive industrial data.

Security First: Prioritizing security is essential when implementing remote access solutions for industrial automation. Industrial VPNs offer a secure alternative to standard VPNs, ensuring that your critical systems are protected against cyber threats.

A Connected Future: As technology continues to advance, the potential for industrial VPNs to create more connected and efficient industrial environments is immense. By leveraging these secure connectivity solutions, businesses can enhance their operational efficiency and stay ahead in an increasingly competitive landscape.


Is a standard VPN safe enough for connecting to my Siemens PLC?

No, standard consumer VPNs are generally not recommended for industrial automation applications. They might lack the robust security features and encryption protocols required to safeguard sensitive industrial data.

What are the risks of using a standard VPN for industrial control systems?

Standard VPNs might be vulnerable to cyberattacks, potentially exposing sensitive control data to unauthorized access. Additionally, they might not offer features like user access control or network segmentation, which are crucial for industrial environments.

What are the benefits of using an OpenVPN connection with my Siemens PLC?

OpenVPN offers strong encryption and is widely supported by various industrial VPN solutions and Siemens PLCs themselves. It’s also relatively flexible for configuration, allowing customization for specific needs.

Do I need any special hardware to use an industrial VPN with my Siemens PLC?

Not necessarily. Some Siemens PLCs offer built-in VPN functionality, and you can use a software VPN client on your remote device. However, dedicated hardware VPN clients can offer advantages like ease of use and improved security features.

How can I ensure a secure remote connection to my Siemens PLC?

Several steps contribute to a secure connection:

  • Use an industrial VPN solution with proven security features.
  • Configure the VPN connection on both the Siemens PLC and the remote device following best practices.
  • Implement strong user authentication methods (avoid simple passwords).
  • Consider additional security measures like multi-factor authentication and network segmentation (if applicable).
  • Maintain updated software and firmware on all connected devices.