Controllers evolve as information needs grow
It seems as though everything we do today is designed to help us do more, and go faster than we have in the past. That’s certainly the challenge facing manufacturers, with plant managers constantly seeking ways to make their production lines faster and more efficient.
U.S. automakers are changing manufacturing strategies to address changes in customer preference, new emerging markets, aggressive competition and rising fuel prices. Food companies are challenged with shorter production runs of a wider range of products, fine-tuned to regional tastes. Pharmaceutical companies are realizing that their competitiveness can no longer hinge solely on the next blockbuster drug.
Control system platforms have evolved significantly to help companies meet these needs. The first programmable controllers were little more than electronic relay replacements, but today’s programmable automation controllers (PACs) have become critical operational tools. As part of a plantwide solution, PACs can deliver control across multiple plant floor disciplines, and also feed data into software applications that convert it into information for better executive decision-making. Three of the most significant recent advancements in controller technology include flexibility, communications network capabilities, and scalability.
Many disciplines, one controller
It’s actually quite rare for a plant to have only one mode of manufacturing. Most instead require a mix of discrete, drive, batch, process, safety and motion control applications. In the past, this range of applications had forced engineers to use multiple controllers: a PLC for discrete control, a motion controller for multi-axis control applications, and a distributed control system or loop controller for process applications. This approach proved time-consuming and costly.
Today’s most advanced PACs feature the ability to handle all these applications from a common control platform. The result is faster startups through re-use of programming tools, lower maintenance costs through reduced spare parts, better information sharing among applications, and fewer support personnel throughout the plant.
A prime example of the value of multidisciplined control comes from Haldor Topsoe, a Houston-based manufacturer of chemical catalysts. The company needed a controller could handle process, motion, and discrete operations. By upgrading control systems on its processes and machines to Allen-Bradley ControlLogix PACs, the company was able to successfully manage overall control functions and communicate information to the human machine interface (HMI) for supervisory-level monitoring and decision-making. Because of the tight integration between the PAC programming software, HMI software, controller, I/O and networks, Haldor Topsoe significantly reduced development and commissioning time, reduced batch variability by 15%, and increased overall plant efficiency by 20%.
One open network protocol
Delving into the inner workings of a manufacturing facility’s control system several years ago would have exposed a plethora of incompatible networks — ones that required complex bridges and drivers to allow information to flow from one to the next. Not only was information flow hindered, but engineers found it difficult to get information from one level of the application to the next level.
Since then, control system networking has improved tremendously, with networks sharing a common protocol for the device level, control level, information level or specialized safety applications. One such example is Common Industrial Protocol (CIP), which was first introduced within DeviceNet in the early 1990s, and has since been incorporated into a range of other networks, including ControlNet and EtherNet/IP.
In addition, easy bridging and routing has transformed control system networking. This has provided manufacturers with the ability to move information from the device level to executives at the enterprise resource planning (ERP) level without new protocols and drivers. Engineers can program and maintain one open network without proprietary languages and code.
Ethernet, in particular, has delivered significant benefits for manufacturers. EtherNet/IP, which is standard Ethernet, allows users to effectively manage real-time control and information flow throughout the manufacturing and IT enterprise. Using the Common Industrial Protocol, EtherNet/IP also allows networks, including motion and safety networks, to communicate seamlessly on the factory floor with other common sets of IT capabilities like video, data and telephony. With EtherNet/IP, manufacturers are able to disseminate data from plant floor controllers, devices and information systems to other parts of the company. Easy access to such information is critical to making informed decisions about the capacity of an enterprise.
Control platform scalability
Today’s most versatile PAC-based control systems also allow the user to more closely match the controller to the needs of the application without compromising functionality or learning a new control system. Such scalability reduces the headaches and high cost associated with system redesign, lack of program re-use, and re-training. Many PLCs of the past required the end user or OEM to learn different programming software and specify networks depending on the size and complexity of the application.
At Trico Industries, an OEM that creates large seat assembly systems for automotive manufacturers, system scalability and ease in programming is imperative due to the immense size of systems. A recent application used an Allen-Bradley ControlLogix PAC and Rockwell
The five work cells then used another Logix PAC, the Allen-Bradley CompactLogix L35E, along with Allen-Bradley Versa-View CE operator interfaces to provide operators with supervisory-level control and monitoring. The scalability of the control platform helped Trico Industries to increase overall manufacturing capacity and build a system with 57% more tracks than systems they typically build. In addition, with the control and information system integrated, the company reduced labor by 200,000 hours and increased overall production rates by 45%.
Controllers have evolved over the years from relay boards that automate a machine to the tag-enabled multidisciplined controllers today. As an information-enabled controller, PACs will continue to evolve along with the information systems executives find useful.
Related reading from Control Engineering includes:
Analysis: PLCs vs. PACs
PACs offer enhanced configuration, performance tools
Programmable automation controllers (PACs) represent an evolution of controller technology in terms of flexibility, networking and scalability. They also come with many new and better selection, configuration and performance tools so users can find just the right controller for the job. Rockwell Automation’s Integrated Architecture website, for example, has a range of tools related to the Logix Control Platform. Visit the Resources Section of the site for links to the following.
EtherNet/IP Performance Prediction Tool
The EtherNet/IP Performance Prediction Tool is intended to help you in the initial layout of your EtherNet/IP network by calculating resources (Connections, Packets Per Second) used by a proposed network. You choose icons to indicate the type and number of nodes on the network, along with associated parameters such as Update Rate desired. The tool then calculates the resources used and what’s still available. This format makes it easy to try different configurations/parameters and see how the outcome is affected.
CompactLogix System Quick Start — updated
These Quick Starts include configuring systems comprised of CompactLogix programmable automation controllers, PanelView Plus, POINT I/O, Kinetix motion and PowerFlex drives on EtherNet/IP, ControlNet and DeviceNet networks. Updated for Logix 5000 version 16 and a new Quick Start that covers the L4x controller.
Integrated Architecture Bookshelf
The Integrated Architecture Bookshelf contains links to many of the most useful documents including QuickStarts, user and reference manuals, and design guidelines.
Kinetix Accelerator Toolkit
With these easy-to-use tools and templates, you spend your time developing the unique features of your machine — not on the routine tasks that add to overhead costs. Order the complete CD (IASIMP-SP004D-EN-C), which contains all files, from a local Rockwell Automation distributor or use the links to download individual pieces.
Sample Code Library Website
This site allows you to retrieve samples of code that have been developed by other users and post code that you think others might find helpful. The Sample Code Library site is a place to share best Integrated Architecture applications, including logic, HMI and drive.
Performance and Capacity Resources — Updated
Reference the most common configuration, performance and capacity information regarding small Integrated Architecture systems.
Performance and Capacity Guidelines
The new Logix5000 Controller Design and Considerations manual provides guidelines for all Logix-based systems. The CompactLogix System Performance and Capacity Guidelines [PDF] include design considerations that can be used to achieve optimum performance from a CompactLogix system.
Faceplate/Add-On Instruction Sets
Adding a device, like a PowerFlex drive, into a Logix controller project has always provided ready-to-use tags. Now Faceplate/AOI sets make use of these tags with pre-written code for your controller and graphics for your HMI. Simply pick and download a Faceplate/AOI set from the library and install and configure it for your application using the straightforward instructions included in the download. By implementing these pre-programmed, pre-tested Faceplate/AOI sets for devices such as drives, networks, and I/O cards, they can be used to configure, commission, operate and maintain these devices without the need to write a single line of code. This dramatically reduces development and debugging time. Faceplate/AOI sets bring the power of the Integrated Architecture to your controller and HMI quickly and easily. Here are just some of the Faceplate/AOI sets available: PowerFlex drives, E3 overloads, analog and digital I/O cards, and Kinetix servo drives.
Integrated Architecture Videos
A collection of Integrated Architecture videos quickly demonstrates important differentiators. A video on Programming Languages in RSLogix 5000 explains the four programming languages available in RSLogix 5000. The Descriptive Logix Tags with DeviceNet video clearly shows the five easy steps to generating descriptive Logix tags using DeviceNet, eliminating the need to count bits or search through manuals. The User Defined Structures video shows a side-by-side comparison between the Rockwell Automation Integrated Architecture and a conventional approach to memory allocation, and how much faster and easier it is to design and allocate memory when using the Integrated Architecture.
RSLogix 5000 Start Page Videos for New Users
These media files are designed to help both first-time customers get started and more experienced customers learn how to use the software to accomplish specific tasks. Media clips and tutorials include: Get Started, Get Connected, and My First Project that show a user how to use the software to complete common tasks.
Introduction to Add-On Instructions
Creating Add-On Instructions
Using Add-On Instructions in a Routine
Monitoring Add-On Instruction Code
Changing an Add-On Instruction
Protecting an Add-On Instruction
Using an Add-On Instruction in a New Project
Integrated Motion for OEMs Video
This video demonstrates how Rockwell Automation can reduce an OEMs’ engineering costs and time to market. It covers such topics as RSLogix 5000 simple motion configuration, scalable architecture and installation savings with Kinetix motion products.
This video demonstrates the benefits of integrating the end user’s enterprise with a single architecture. Rockwell Automation’s Integrated Architecture provides users with the ability to make faster, better business decisions and reduce total cost of ownership.
This side-by-side comparison between Rockwell Automation’s Integrated Architecture and a conventional approach demonstrates how data moves seamlessly from device to control to HMI to the business system.
The Integrated Architecture Value of One illustrates the benefits of Integrated Architecture: Scalable controllers, networks and HMI, using one control programming software package, one networking protocol, one HMI configuration software package and the information enabled attributes of the system across process, drive, motion and discrete control disciplines.
FactoryTalk View Machine Edition Quick Start Videos
These media files are designed to help both first-time software users get started and more experienced users learn how to use the software to accomplish specific tasks.
|Lee Lane is Logix marketing manager for Rockwell Automation.|