Process Control Systems
Our staff includes specialists in control system engineering, from single-loop PID control to large scale, multi-variable systems with significant interactions between multiple actuators and numerous simultaneous control objectives. We have extensive experience in the design and implementation of real-time computing platforms, including high-speed interfaces to processes and people.
Our control engineers specialize in analyzing the physical characteristics of a system, identifying performance constraints, and applying real-time control and systems technology to achieve performance objectives. Typical specifications include accuracy (target following), precision (repeatability), speed of response, and/or disturbance rejection.
Though the theory underlying these systems often involves complex mathematical derivations, our approach emphasizes practical application and understanding of the technology. We realize that the technology only produces value for our customers when it is implemented for results and can be understood by support personnel. We have a successful record of providing practical, application-oriented training to plant technicians and engineers.
Real-Time Computing Platforms
Implementation of digital process control systems requires an integrated real-time computing environment. The functions of such a system include:
- Input/output data processing
- Sequencing and event-based processes
- Control algorithm execution
- High-speed communications
- Human-machine interfaces
- Process monitoring and diagnostic facilities
- Real-time and historical data trending tools
- Performance reporting
- Software development facilities
A key requirement for real-time process computers is the execution of signal sampling and control algorithm tasks at specified periodic time intervals. These intervals must be deterministic and repeatable, regardless of the level and nature of CPU loading, in order to assure that the control algorithms operate as designed.
TelePro and SSE have extensive experience in real-time computing systems. Our Tsentry computing platform product is an open-architecture real-time system that runs on standard personal computer hardware. Over 80 Tsentry systems are in operation worldwide, performing rolling mill control, motor drive control, smelting process control, non-destructive product inspection, data acquisition, process monitoring, shop floor control and plant scheduling.
We also have broad experience with other real-time systems, including: PLC's, UNIX-based systems and industrial drive controls. General services related to real-time computing platforms include:
- System configuration, integration, and testing.
- Operating system selection and support.
- Human-machine interface systems.
- Process signal input/output interfaces.
- Computer communications.
Computer System Communications
Our staff includes recognized experts in the field of computer-to-computer communications. Manufacturing control systems require the integration of increasingly sophisticated and complex components, and we have engineered solutions that satisfy both factory production and management information goals.
We have developed a suite of communication drivers for interfacing various types of computers, including MIS business systems, process control computers and PLC's. We also routinely develop custom software to interface instrumentation to data acquisition and control computers.
Process Monitoring and Diagnostic Systems
Many of our process control systems include monitoring and diagnostic functions to improve maintenance, data collection and troubleshooting capability. We also provide product quality and performance monitoring tools.
The TelePro Tsentry real-time process computing environment includes several built-in process monitoring and diagnostic facilities. These include real-time and historical data trending utilities, graphical control system maintenance and troubleshooting displays, and alarm/event recording.
We have developed several systems for acquiring product quality and processing history information and recording this data in relational databases. For example, our rolling mill automation products include a system that collects real-time thickness and flatness performance data. Sensor data is recorded for the entire length of each coil processed and archived in individual files for each coil. It can be plotted in real time, as the coil is running, or off-line from the historical archive files.
Production Control Systems
We engineer systems to perform inventory control and tracking as well as shop floor scheduling. These systems typically utilize relational production databases accessed from a variety of points within the factory. Our systems are in wide use in metal and glass manufacturing and processing.
The requirements for these systems include:
- Providing a human-machine interface system for shop-floor operators.
- Receiving and storing production schedules from the MIS plant scheduling system.
- Managing and sending setup information to the process controls.
- Tracking and recording production operations as they are performed.
- Tracking material flow through the plant.
- Tracking equipment downtime and asset utilization.
- Maintaining production center crewing statistics.
- Creating interfaces to share process data with other plants.
- Gathering and storing quality-related data for the process.
- Gathering and storing real-time data from the process controls.
For larger factories we have interfaced wireless terminals and hand-held computers to the production database for mobile applications. These systems typically access a central production schedule to retrieve target and setup information for individual production centers.
In laboratories, engineers and scientists conduct experiments and produce data that determines the direction and ultimate success of their work. Reliability engineers are concerned with quality and reliability of manufactured products. Many of the requirements of laboratory and test computer systems are similar.
In most cases, a variety of data acquisition and control instrumentation must be interfaced with data collection computers. These interfaces generally employ serial (RS-232, RS-422, RS-485) or parallel (IEEE 488, GPIB) protocols. Instrumentation interface hardware may also be added directly into the data acquisition computer itself.
Our laboratory/test system specialists have experience in setting up these systems and interfacing the necessary instrumentation. We work with clients to choose commercially available software and hardware to meet system requirements. When necessary, we also engineer and deliver custom solutions.
Client Product Development
On many occasions our clients have involved TelePro/SSE in their product development. We have helped develop and maintain several products that have made our clients successful.
In these situations, a new product concept or idea is developed by the client and requires computers or electronics to bring it to market. We can advise the client on implementation strategies, plan the development cycle, provide engineering and design support, and build product prototypes. We can also coordinate manufacturing.
Of course we hold all client information confidential. Our goal is to enhance the client's expertise by providing expert technical support to make the products successful.
Graphical Human-Machine Interfaces
Our staff has been involved in graphical human-machine interface (HMI) systems for many years. Before such systems were commercially available we designed and implemented an HMI system that interfaced IBM PC workstations running DOS to a wide variety of commercial process control host systems. This system was installed in multiple plants in the USA, Europe, and Australia. Many of these installations remain in use today.
More recently, the graphical HMI for our Tsentry real-time process computing system is implemented using standard Internet web pages hosted by the Tsentry system. Displays are developed using a combination of Microsoft Visual Basic .NET and Active Server Pages. Complete facilities for developing and publishing custom HMI displays are provided to the end user. This design permits any network-connected PC workstation with a standard web browser and proper security credentials can be used as an HMI client, eliminating tag and client licensing issues.
We also have experience delivering systems using many commercial HMI systems, including: Wonderware/InTouch, Citect (CI Technologies Pty. Ltd.), Sybase PowerBuilder, National Instruments LabVIEW, and Rockwell Automation/Allen-Bradley PanelView.
Simulation / Modeling
Dynamic modeling of physical systems is a key area of emphasis for control engineers. Designing and implementing real-time automation systems requires a thorough understanding of the dynamic behavior of the target process. That is, both its steady-state response to control actions and disturbances and the transient trajectory it takes to reach steady state. At the heart of any high-performance control system is a dynamic model of the process. From this model, the control engineer determines how the process dynamics must be changed to satisfy the performance specifications. In the end, control system performance is only as good as the dynamic model on which it is based.
Our control engineers have substantial formal training and practical experience in dynamic modeling of physical systems. This expertise is used to develop dynamic process simulations that mimic both steady state and transient system behavior. Such simulations are used to:
- gain insight into process behavior,
- formulate physically-based control strategies, and
- compare various control alternatives.
Implementing the dynamic simulation in a real-time computing platform allows it to be used for testing control system implementation prior to actual commissioning. Thus, startup time is minimized and ultimate system performance can be achieved more quickly.
TelePro provides both custom and standardized training programs to its clients. Standardized programs include: rolling mill process training, general control system design and implementation, training in various programming languages, and Tsentry real-time process computing system training.
Our training approach emphasizes practical application in industrial settings. In cases such as rolling mill process training, we provide training where formal courses of study are not generally available.
Recognizing that most courses of study in control engineering tend to emphasize the underlying mathematical theory over practical application in industrial processes, we have developed a process control technology training approach that focuses on the needs of the industrial control practitioner. This approach involves building the necessary mathematical foundation through emphasis on understanding for application versus rigorous mathematical derivation and proof. Though the concepts include several of the same mathematical constructs covered in formal courses of study, they are presented from the control practitioner's perspective. The result is that course participants learn to relate the theory to physical systems. They gain insight into how process behavior is characterized by various mathematical transformations and formulae. This better prepares them to use the theory to design controls that satisfy the necessary performance criteria.
The process control technology training program includes:
- Mathematical foundation
- Practical system analysis techniques
- Continuous-time control design techniques
- Discrete-time control design for digital computers
- Real-time computing environments
This approach to control training has been well received by past participants with a wide variety of backgrounds. It is essentially equivalent to a first undergraduate course in digital process control but with a distinct emphasis on practical application.