What is Fault Tolerance?
Fault tolerant computer systems are designed to assure business continuity and high availability by preventing disruptions caused by a single point of failure. As a result, fault tolerance solutions tend to concentrate on mission-critical applications or systems.
There are multiple levels of tolerance in fault-tolerant computing:
- At the most basic level, for example, the ability to respond to a power outage.
- A step up: the ability to use a backup system instantly in the event of a system breakdown.
- Improved fault tolerance: if a disc fails, mirrored discs take over instantly. Rather of an immediate breakdown and loss of function, this permits functionality despite partial system failure or graceful degradation.
- High-level fault tolerant computing: several processors work together to examine data and output for faults and then rectify them promptly.
Define Fault Tolerant Ethernet (FTE)?
Fault Tolerant Ethernet (FTE) is supposed to enable immediate network redundancy. The dual network interface controllers link each node to a single LAN twice. When the primary route fails, the driver and the FTE-enabled components allow network communication to occur over an alternate route. Honeywell invented the FTE.
Redundancy of Ethernet connections and network infrastructure is used to build fault-tolerant networks. Dual Ethernet connections are employed in the event of a server or workstation. Various switches are used with multiple network connections in what is commonly referred to as a “fabric” in the case of network infrastructure (switches, etc.).
Because switches must direct traffic based on changes in network topology, redundant network connections place additional demands on infrastructure. Additionally, the switches must prevent “loops” in which network packets might become caught, resulting in increased network traffic. This means that if fault tolerance is necessary, controlled switches must be employed.
FTE Network Levels
Level 4 - Plant Level Applications
Level 3.5 - DMZ
Level 3 - Non-critical Control and Advanced Control Applications, Routing
Level 2 - Supervisory Control, Operator HMI
Level 1 - Real-Time Control (Controllers and I/O)
Level 2 is home to the majority of Experion nodes, including Experion Servers, Console Stations, ACE/ACE-T nodes, Flex Stations, Application Nodes, E-APP Nodes, ELCN Nodes, EtherNet I/P Interface Nodes, and much more.
At Level 1, these nodes must communicate with devices such as the C300/C200 Experion Controllers.