Modernizing Transit SCADA Systems with Proficy®

Urban transit systems face increasing pressure to deliver reliable, safe, and efficient services amid growing ridership and aging infrastructure. This Transit Authority operates one of the most critical transit systems in the United States, serving millions of passengers annually. They needed to modernize their control systems to ensure real-time monitoring, rapid response to incidents, and seamless integration with existing assets.

They partnered with Avista Realtime Systems, LLC (Avista) – due to their deep knowledge and expertise in power automation – to enhance their operational efficiency, safety, and reliability with a more open SCADA system that would allow them to add all their assets and empower their operators with data and analytics. The project aimed to replace traditional control room operations with a robust, scalable, and secure SCADA solution. Avista decided to build this new SCADA solution on the Proficy® platform by Velotic as it’s mature, tested, and up-to-date. They knew Velotic’s Proficy® iFIX HMI/SCADA could provide the functionality they needed – utility-grade scale of platforms in many different verticals and secure integration with Proficy® Historian, without much configuration or custom programming, to empower their client’s management and engineering teams with real-time monitoring, alarm management, and event analysis. This system provides a comprehensive framework for data acquisition, supervisory control, and operator interaction, tailored to the rail transit operator’s unique operational environment.

“Modernizing a mission critical transit SCADA system requires a platform that is proven, flexible, and secure. Proficy software allowed us to integrate legacy assets, enhance real-time visibility, and provide operators with actionable data while maintaining the reliability required for a large urban rail network.”

President Avista Realtime Systems

The modernized SCADA system – integrated by Avista and built on Velotic’s Proficy® platform, is a distributed, open-architecture solution designed to manage data from remote terminal units (RTUs) across various transit stations. Its architecture integrates several core components:

• Data Acquisition and Communication
  
  At the heart of the system lies the Proficy® redundant SCADA server, which polls data from RTUs deployed at station assets using the Distributed Network Protocol (DNP3.0). The DNP3.0 driver, a native Proficy component, supports up to 1,000 server devices across 200 channels, utilizing both serial and IP-based communication (TCP/IP and UDP). This flexibility enables reliable data transfer over diverse mediums, including fiber optics, copper wire, and radio, ensuring resilience in varied operational conditions. The driver’s features—such as sequence of events, report-by-exception, and automatic failover—enhance data integrity and system uptime, critical for real-time transit operations.
• Real-Time Database and Processing
  
  The Proficy® process database serves as the central repository for real-time data, utilizing a block-and-chain structure to execute control logic. Primary blocks handle input/output operations with configurable scan times, while secondary blocks perform calculations and actions based on upstream data. The Scan, Alarm, and Control (SAC) program processes this data, supporting time- based, exception-based, and one-shot processing strategies. This adaptability allows this large rail transit operator to balance resource allocation, processing critical data rapidly (e.g., every 0.05 seconds) while managing less urgent data over longer intervals.
• Human-Machine Interface (HMI)
  
  The Proficy® WorkSpace provides an integrated development environment (IDE) for operators, featuring customizable graphical displays. These HMI screens—such as the AC Room and Traction Power Substation (TB and TPSS) interfaces—visualize real-time data (e.g., breaker status, bus voltages, transformer temperatures) using animations and templated designs resolved via Tag Group Definition (TGD) files. The system’s web server extends this capability, rendering HMI pictures to users across the corporate network, enhancing accessibility without compromising security.
• Historian and Data Analytics
  
  Historical data collection is facilitated by Proficy® Historian, a collector which samples real-time database values and stores them for analysis. Integrated with SQL-based querying tools like Historian Interactive SQL, this component enables this large rail transit operator to generate reports, trend analyses, and event logs. Visualization tools, such as VisiconX and multi-line charts, present this data in actionable formats, supporting predictive maintenance and operational decision-making.
• Security and Redundancy
  
  Security is paramount in this modernized SCADA system, with Proficy® and Windows-based authentication protecting against unauthorized access. Security areas restrict database writes to authorized personnel, while a firewall safeguards the Proficy® server, Historian, and web server. Distributed networking ensures redundancy, allowing nodes to operate independently and maintain functionality even if a segment of the network fails.

The deployment of this large rail transit operator’s bespoke SCADA system was executed with a focus on scalability, engineering training, and minimal disruption to ongoing operations. Key phases included:

• Infrastructure Assessment: Mapping RTUs and existing assets to design a tailored data acquisition network.
• System Configuration: Installing Proficy® and the DNP3.0 driver on SCADA servers, configuring channels/devices, and templatizing HMI displays for station-specific needs.
• Operator Enablement: A comprehensive training program, delivered by Avista, equipped the large rail transit operator’s staff with skills to configure, monitor, and troubleshoot the system. Sessions covered SCADA fundamentals, database management, graphics development, and Historian integration.
• Testing and Validation: Simulation points and real-time data feeds were used to verify system performance, ensuring accurate alarming, data logging, and HMI responsiveness.

The system’s open architecture, leveraging standards like OPC, ActiveX, and ODBC, facilitated integration with third-party applications and future upgrades, ensuring long-term adaptability.

The system has delivered measurable improvements across operational, safety, and maintenance domains:

• Enhanced Situational Awareness: Real-time HMI displays provide engineers with immediate visibility into asset conditions, such as breaker statuses and bus voltages. Alarm management features—supporting selective routing, and filtering—enable rapid incident response, reducing downtime and enhancing passenger safety.
• Improved Efficiency: By implementing this project, this large rail transit operator has streamlined monitoring and managing the system. The distributed processing model minimizes single points of failure, while on-demand data transfer optimizes network bandwidth, supporting efficient resource use across a large transit network.
• Data-Driven Decision Making: The Historian component transforms raw data into actionable insights, enabling trend analysis and predictive maintenance. For instance, transformer temperature trends can preempt equipment failures, while SQL queries of event logs support compliance reporting and operational audits.
• Scalability and Futureproofing: The system’s modular design and support for up to 1,000 devices allow this large rail transit operator to expand coverage as new stations or assets are added. Integration with web-based interfaces and third-party tools ensures compatibility with emerging technologies, protecting the investment over time.

The project demonstrates the power of modern automation in transforming transit infrastructure management. By integrating advanced SCADA technology with a robust training framework, this large rail transit operator has established a resilient, efficient, and secure management system that meets the demands of a dynamic urban environment. This initiative not only enhances current operations but also positions them to adapt to future challenges, setting a benchmark for transit authorities worldwide.

This case study underscores the importance of scalable architecture, operator empowerment, and a focus on real-time data utilization. As urban transit systems evolve, solutions like this will remain critical to delivering safe, reliable, and efficient services.

Avista Realtime Systems, LLC is a full-service SCADA system integrator providing end-to-end, turnkey SCADA solutions. Avista serves as the single accountable SCADA System Integrator, assuming full responsibility for system design, integration, testing, commissioning, and operational performance