Explosives control system bolsters safety, performance

Australia boasts world-class capabilities to manufacture propellants and high explosives. To retain these capabilities and ensure ongoing domestic access to munitions and explosives, aging manufacturing plants can benefit from investing in new technologies.

Technology challenges facing explosive manufacturers today include replacing aging control systems on equipment that may not be supported, with modern platforms and integrating control and safety to support ongoing increased demand.

When a leading explosives manufacturer decided to undergo a complete control system upgrade, they took the project to tender. As a result of this process, SAGE Automation, a leading provider of industrial automation and control services, was engaged to develop a solution to cater for both current and future requirements.

In particular the company needed to:

• upgrade existing DCS, PLC and SCADA controllers and associated control gear for a number of physically separated process areas responsible for a variety of machine, process and safety control

• develop a solution that complies with hazardous areas, functional and machine safety standards and regulations

Seamless integration

The control system of the high explosives plant is responsible for a variety of machine, process and safety control functions in a number of physically separated process areas.

SAGE Automation was tasked with developing a new solution to replace unsupported hardware with current day platforms and technology.

According to Steve Lloyd, senior project manager at SAGE Automation, “The new control system was required to be integrated across 17 process buildings and also include a new control room fit out, while ensuring the safety instrumented system complies with today’s current standards. This scope included upgrades to the distributed control system (DCS), programmable logic controllers (PLC), operator interfaces, network infrastructure and the delivery of a simulation system for operator and maintenance personnel training.”

In executing the control system upgrade, there was a focus for best practice design, high availability system and an integrated architecture from plant controller through to reporting and asset management.  To achieve this, a detailed design process together with an integrated architecture from process controller through to enterprise level reporting and asset management was successfully implemented.

“After investigating a number of options, we found that the Rockwell Automation PlantPAx® process automation system with ControlLogix® Integrated Architecture® and AADvance® fault tolerant system was the best choice for this application to provide integrated control and safety,” said Lloyd.

Integration on this scale with the Rockwell Automation solution allowed for full use of the pre-integrated functionality within each individual product resulting in rapid deployment, pre-validated software function and access to information and diagnostics key to operational efficiencies.

The PlantPAx process automation system delivers all the core capabilities expected in a world class distributed control system (DCS). The system is built on a standard-based architecture using Integrated Architecture components that enable multi-disciplined control and seamless integration and scalability to support ongoing increasing demand.

The AADvance fault tolerant control system is a truly distributed scalable architecture which comprises of both a hardware controller and a software environment that allows the user to apply different levels of module redundancy as required by specific parts of their application.

“It is a reasonable size installation and a state-of-the art control system. The solution is the result of an innovative design in terms of the way the control system is architected, moving away from traditional centralised models and employing a decentralised virtualised architecture which still maintained and utilised the full functionality and capabilities of the PlantPAx and AADvance platforms,” explained Nigel Dezdjek, solution architect at Rockwell Automation.

Back up plan

Being an explosives manufacturing plant, introducing redundancies across a number of control system layers was paramount for safety reasons. The customer highlighted the specific requirement for the provision of complete control from the local process areas. Consequently if there was a loss of control path between the main control room and a process area, complete control was still required in that process area to facilitate a safe and controlled process shutdown.

To achieve this, the architecture design was modified to separate the primary and standby SCADA servers across locations. This satisfied the requirements although now the solution required a larger number of hardware components to achieve this. The PlantPAx platform provided an effective and reliable solution for this redundancy.

A key feature of this solution is the HMI fault tolerance; allowing each building to continue to function independently and provide local control functions in the event of a network outage.  In addition, high availability ensures that a failure of the primary HMI server node at each building location will not prevent the system from running, as the secondary HMI server in the control room data centre will take over.

The plant operator interface consists of four dual monitor FactoryTalk® View SE clients within the central control room and nine dual monitor FactoryTalk® View SE clients distributed throughout the process areas, all served by a distributed redundant HMI server configuration. The system installed is a dual redundant system with 2-1-0 degradation so that if a module fails, the system degrades to single control and if the last module were to fail, the system would shut down.

This solution also allows the management all projects from the centralised engineering work station and avoids the need to duplicate changes to a standalone project for each process area.

“We implemented redundant process controllers within critical process areas at the building level, with the overall facility connected via a redundant fibre optic Ethernet network.  Redundant power supplies were also implemented to provide redundancy in the power supply system,” said Lloyd.

“A redundant uninterruptable power supply (UPS) architecture was implemented, which included seven redundant and 11 non-redundant UPS systems, totalling 34kW of back-up power. This provides greater than one hour back up time across all PlantPAx and AADvance controllers, HMI servers and clients, network switches and process instrumentation,” he said. 

Virtualisation and customisation

Due to the size and complexity of the control architecture of this facility, SAGE designed and implemented a virtualised server environment and associated network architecture to satisfy and exceed the specific site requirements. The network infrastructure involved a new fault tolerant Gigabit fibre Ethernet network, utilising a Cisco and Rockwell Automation Stratix™ managed switch configuration to connect the 50 hectare facility.

“PlantPAx is based on open IT standards and networks, allowing all PlantPAx workstations and servers to be easily virtualised. By creating virtual machine templates and deploying them across virtual machine hosts, it made the deployment faster and reduced engineering time, it also increases flexibility as you can easily move virtual machines between hosts, allowing you to more easily set up redundancy within the virtual environment,” explained Lloyd.

“Additional benefits that virtualisation brought to this project included reduced power consumption, and centralised management of the virtualised environment which equates to lower running and support costs. Also part of that same architecture is the use of thin HMI clients which are low cost computers with a small physical footprint that typically have a higher environmental rating and are more robust than traditional PC based clients,” he said.

This solution used a lot of different product offerings from within the FactoryTalk suite of products to deliver a fully integrated solution. FactoryTalk Historian and VantagePoint were used for all trending and reporting, FactoryTalk AssetCentre was used for asset management and FactoryTalk View was used for the HMI component of the PlantPAx solution.

“Another benefit of using the FactoryTalk platform for this solution was that it is flexible enough to customise. We were able to customise the Rockwell Automation Library of Process Objects standard templates and develop custom code within the FactoryTalk environment where required to satisfy specific customer requirements and provide additional unique functionality which, at the time, was not standard out-of-the-box, including tag search, trend page tools and cross navigation,” said Lloyd.

Solutions technology

• PlantPAx® Process Automation System combines plant wide control with scalability of Integrated Architecture®.
• ControlLogix® with Studio 5000® software.
• FactoryTalk® integrated production and performance suite.
• AADvance® fault tolerant control system.

Meeting the customer’s unique requirements and specifications was a key priority for Rockwell Automation and SAGE. 

“We successfully delivered a completely integrated control and safety solution that maintains functional safety compliance to AS61508 and Hazardous Area regulations, AS60079,"said Nigel Dezdjek, Solution Architect, Rockwell Automation.

"The new solution provides enormous benefits around a common approach and platform to provide all the functionality within the system," he said. 

"Downtime was also minimised during installation as the solution was delivered around the plant’s normal operating schedule." 

Meeting safety standards:

• Compliance with Functional Safety standard AS61508 and Hazardous Area regulation AS60079. Seamless integration

• PlantPAx provides a seamless integrated solution.

• Ability to support ongoing increasing demand.

• AADvance solution provides distributed scalable architecture with flexible module redundancy.

Connected, integrated system:

• EtherNet/IP™ used to connect DLRs and reduce installation time and cabling.

• Stratix™ managed switches provide the ability for a number of managed virtual LANs.

Manufacturing intelligence:

• FactoryTalk suite of products delivered a fully integrated solution.