SCADA System Design Technical Requirements

Supervisory Control and Data Acquisition (SCADA) systems are used in a variety of industries to monitor and control processes across a distributed network. SCADA systems are critical to the functioning of many processes and organizations, and as such, system designers must ensure that the system is as efficient and reliable as possible. Achieving this goal requires careful consideration of a variety of factors, including communication protocols, network architecture, and system redundancy. This article will discuss the design requirements for SCADA systems in order to ensure high efficiency and reliability.

Introduction to SCADA Systems

SCADA systems are used to monitor and control processes from a remote location. The system consists of a master station, which is connected to a network of RTUs (remote terminal units) or IEDs (intelligent electronic devices). The RTUs are connected to the process and collect data from the various parts of the system. The data is then sent back to the master station, where it is used to monitor and control the process.

The SCADA system is typically used in industrial applications such as oil and gas, water and wastewater, and power generation. It is also used in many other applications, including transportation, security, and manufacturing. The SCADA system is designed to be highly reliable and efficient, and as such, great care must be taken when designing the system to ensure it meets the needs of the application.

The SCADA system is designed to meet the specific requirements of the application. The design requirements must be carefully considered in order to ensure the system is as efficient and reliable as possible. The following design requirements should be taken into consideration when designing a SCADA system.

General Requirements

A detailed performance analysis should be conducted for each application to determine the optimum architecture to meet the performance requirements of the application. The analysis should address SCADA server loading, bandwidth capacity and utilization of each telecommunication channel, and should be based on the expected data scan frequency and spare capacity for each application.

The communication protocol(s) used to communicate with the RTUs and other system components should be based on open industry standards. All functional requirements should be implemented using the protocol’s standard features, and any optional protocol functions used to meet application-specific requirements should be fully documented.

SCADA Design Architecture

The SCADA host station software should be based on a client/server architecture, with the processing load balanced and distributed among the system components to achieve scalability and highest performance level. The master station should consist of online redundant SCADA servers connected by a redundant high-speed local area network (LAN) using dedicated Layer 3 network switches.

The SCADA LAN should be physically and logically isolated from all other non-SCADA network traffic. The SCADA server(s) should be dedicated to performing the real-time data acquisition and telecommunication processing functionalities and should not be shared or used for any non-SCADA related data processing functions.

Operator workstations located in the main control center should run thick client software, and remotely located engineering workstations and view-only workstations should be connected to the SCADA network through a logically separated 2 Mbps data link as a minimum. For applications requiring continuous data access, such as software modeling applications, a 10 Mbps data link should be provided.

Availability and Reliability

The SCADA system architecture and telemetry network design should provide a 99.50% hardware and software availability and reliability. The system should also be designed so that SCADA communication network flooding generated by a faulty communication device does not block the network, cause network jamming or degrade system performance.

The SCADA host station should be designed with no single point of failure, and replacement of any failed SCADA LAN components should not affect operations of the process. The system should continuously monitor and test all backup equipment to determine whether the backup equipment is capable of assuming primary equipment functions.

Conclusion

SCADA systems are critical to the efficient and reliable operation of many processes and organizations. As such, great care must be taken when designing the system to ensure it meets the needs of the application. This article has discussed the design requirements for SCADA systems in order to ensure high efficiency and reliability. Proper consideration of these requirements will ensure a successful SCADA system installation.

SCADA System Design Technical Requirements

Introduction to SCADA Systems