Industrial IoT requires a system change in field operation

Purely hardware-bound control and data transfer architectures are less and less able to deal with the ever-increasing volume of information. As a consequence, virtual machines or cloud systems have become established as more flexible, almost freely and quickly scaleable solutions. To ensure constant, secure access to process values, system status and production and maintenance processes from the field to the control station, both the hardware and the software of the field operating devices must meet the requirements of process and system control. Thin Clients with software optimised for the industrial Internet of Things are replacing traditional standard computers and KVM systems for remote access to distributed control systems.

Compared with industrial PCs in the field, operator stations with a remote connection are the more compact, energy-efficient and low-maintenance solution in hazardous and non-hazardous areas. However, the classic version of a fixed connection between an explosion-protected HMI system and a workstation in a safe area is still quite common in the process industry. It consists of a remote terminal that is connected to a KVM box via a copper or FO cable. The KVM box in turn is connected to the keyboard, video and mouse interfaces of a PC workstation to transfer screen data to the remote terminal, and the input from the keyboard and mouse to the computer. With the use of fibre optic, transmission distances of up to 2 km can be covered. Current USB standards such as USB 3.0 or 3.1 are difficult to handle with such concepts, since the connected USB devices such as keyboard, mouse or touchscreen may fail due to interferences from the industrial environment, making it necessary to restart the host. Also, these systems lack the flexibility to be integrated seamlessly into higher network levels.

Classic KVM systems cannot be connected directly to virtual workstations. They do not have the physical interfaces for the keyboard, video and mouse, and these must be provided by another PC or Thin Client. While this type of hardware constellation is possible, it is much more expensive with regard to purchase price, commissioning and maintenance. The connection of operating and monitoring systems in the field to process control technology and higher network levels thus requires operator stations capable of connecting to a wide range of server architectures, including virtual machines and cloud automation.

Thin Clients  provide a future-proof operating solution for the process industry, from the control centre to the field, but must be optimally tailored to the requirements of modern industrial networks and be compatible with all current control systems from leading manufacturers. The most important requirement is IT security.

Thin Clients  should be closed, tamper-proof systems that can only be parameterised with password protection, for example. Integrity and availability are important characteristics of the firmware of these systems. Security features such as the Unified Write Filter and HORM (Hibernate Once / Resume Many) increase system stability and provide greater fail-safe functionality in industrial environments. Redundant Ethernet interfaces with automatic reconnection ensure fail-safe operation. Third-party applications – such as browsers, apps for the integration of camera images or Citrix – should only be available for secure access in Kiosk mode. Despite these features, the systems must be easy and ergonomic to configure.