PLC backup and restore procedures are proving essential to maintain the integrity of manufacturing systems. They also ensure that the latest software is used and that there is no costly downtime. In addition, asset management is an important component of the foundation of cyber security activities in all types of organizations. Enhanced by the ability to create backups and restore them to a device if necessary, device and update management is one of the building blocks of a proactive, end-to-end security strategy.

Resetting an automation device

To ensure the highest level of cyber security and reliable and predictable performance of automated systems and machines, a process should be developed and established that keeps these systems up to date by installing software and security updates in a standardized, automated and secure manner. This is made possible with the help of a manufacturer-independent device and update management service based on OPC UA.
It always makes sense to generate a backup - and not just for automation devices. There are two use cases for industrial automation systems:

• The device is defective and needs to be replaced.
• The user has to reset the device due to a cyberattack.

The second use case, which also plays a major role in the context of the certification of the controllers in the PLCnext Control product family from Phoenix Contact, is discussed below.

App creates back-ups for control units

PLC backups prove to be essential, as they prevent the program and configuration data stored in the controller from being lost in the event of a hardware failure, power failure or other unexpected events. Without a backup, the program usually has to be recreated from scratch, which leads to downtime and loss of productivity. In addition, the cost of replacing a faulty PLC can be expensive. And without a backup, it can be difficult to restore the system to its previous state. A PLC backup with the device and update management service provides a simple and efficient method of quickly restoring the system to its previous state. In the event of a security emergency, the backup can be used to load the program and configuration data onto a new or repaired controller so that the system can return to normal operation with minimal downtime(Fig. 1).

Figure 2: Illustration of the creation of a back-up.

© Phoenix Contact Electronics

In the current version of the device and update management as well as the PLCnext Control series controllers, the 'DaUM Backup and Restore' app generates a backup on the target device and restores a provided backup. The app can be downloaded free of charge from the PLCnext Store.
To perform the backup, the user must configure and authenticate the OPC UA connection in the 'OPC UA Clients & Servers' area. As soon as the app is recognized on the device and the OPC UA file transfer settings correspond to the respective specifications, a backup of the device can be implemented. The backup is either triggered immediately with a click of the mouse or scheduled and carried out regularly. At this point, it is important that a back-up does not affect the processing of the PLC project. The back-up can therefore be created during the ongoing production process and transferred to the device and update management service(Fig. 2).

Protection of integrity and confidentiality

In the use case described, a backup is generated in order to restore it on the same asset. Consequently, data that may be related to the hardware and cannot be used on another asset of the same type can and is also backed up here. The entire list of files contained in the backup is displayed for each backup in the device and update management service. The following is a selection of the most important data for the user:

• the PLC project with the runtime data,
• network settings,
• user settings,
• log files,
• installed apps.