Question

Q4. Name three areas in which you can increase the availability of a SCADA system by introducing redundancy into the design of the system.

Answer 1

Areas in which you can increase the availability of a SCADA system by introducing redundancy into the design of the system

1. Communication Services

The SCADA systems provide low cost solution for for IEC 61850 Client/Server communication using a combination of Link Aggregation and the Rapid Spanning Tree Protocol (RSTP) can meet the performance requirements. The SCADA systems performing critical high-speed functions such as load shedding via IEC 61850 GOOSE require a better failover performance which can only be met with PRP and HSR redundancy protocols.

.High availability is usually achieved through the implementation of a redundant architecture with multiple SCADA systems, each having multiple Ethernet communication interfaces. Ethernet network redundancy isn't only required to supply resiliency against a failure within the communication network but also to permit for the upgrade, removal and reinsertion of networking components without disrupting the in-service system

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2. Industrial Process and factories

Supervisory control and data acquisition (SCADA) systems are widely utilized in plants and factories across the planet. Generally SCADA systems are highly reliable. However, one aspect in their operation that's often overlooked at the specification stage is redundancy.

The question is especially relevant when one considers that control systems for both single-node and network applications have one point of failure, meaning that they're going to break down entirely if one piece of hardware fails (such because the computer connected to the control and monitoring units). Granted, latest computers are designed for reliability, but breakdowns still occur, especially with computers located in harsh environments. Consequently, if some or all of the plant processes are critical, or if the downtime costs are high, redundancy must be incorporated into the system to eliminate failures due to equipment failure.

In the first instance it's important to work out what level of redundancy is required by considering the risks: hardware failure, catastrophic failure, energy failure or a natural disaster? Mission-critical installations often have separate power sources just in case of an influence failure, and installations in areas susceptible to natural disasters or the threat of fireside separate the servers in different geographic locations. However, whatever sort of disaster recovery is planned for, it's possible to greatly reduce lost data and downtime by planning the right system design, and by choosing a SCADA system with built-in redundancy.

3. Water and wastewater treatment

Water and wastewater treatment facilities often require system designs that help ensure uninterrupted operation. Even an interruption lasting but a second can cause systems to reset or pack up, potentially leading to contaminants entering clean water, critical processes not completing fully, or other challenges.

The most common approach to protecting against a possible interruption is that the inclusion of redundant systems i.e. to use SCADA system. Whether they’re integrated into the electrical distribution system, communications network or the automation system, redundant systems increase reliability by taking up if the first controls stop functioning.