Control systems in a package: going "lean" goes beyond production management. It even affects several aspects of control systems hardware, software, and application development.
Bosch Rexroth Corp. (Hoffman Estates, IL; www.boschrexroth-us.com) recently announced plug-and-play control that includes all the necessary hardware and software components--with predefined motion function blocks--for two types of applications: articulated robot pick-and-place and roll feed systems.
IndraMotion for Handling, based on Rexroth's IndraControl L40 motion logic controller, is for Cartesian gantries with up to three linear axes and three rotary axes of motion. This motion is controlled by IEC 61131-based motion function blocks that require a few basic parameters for setup. Depending on what the gantry has to do, between 70% and 90% of the code is basically finished, claims Karl Rapp, automation and machine tool branch manager for Bosch Rexroth, Electric Drives and Controls. Similarly, IndraMotion for Metal Forming has the motion functions for such applications as roll feed, coilers, and traveling cutters. To set up, a user need only enter length, speed, and quantity parameters. This IndraMotion system comes in three versions with differing OEM programming options. One version requires no programming; another lets users program functions blocks to integrate IndraDrives into custom roll feed systems.
The IndraMotion code comes on a CD as "open source." Explains Rapp, the code is finished, but modifiable. "It's not like we compile it and then the user can't do anything with it." The screens are provided as compiled run-time files that can be loaded into Microsoft Windows CE devices, non-CE devices, or PCs. And both IndraMotion packages support SERCOS (fiber and Ethernet), Profibus, and DeviceNet interfaces. "The OEM doesn't have to worry about generating the motion engine or the programming method," continues Rapp. "There's no syntax to learn. Users need only enter, teach, or read the point coordinates from the programmable logic controller [PLC] program or the network connection. All moves are velocity optimized and can be blended. Points can be named so they match the application by simply changing text in the PLC program--no human/machine interface [HMI] change required. The same applies to inputs and outputs, such as grippers."
The benefits are huge. Because the programming methods of the motion itself are standardized, the OEMs only need to focus on the process and integration aspects of their handling or metalworking systems. Engineering and startup times are short. For end users, the standardized programming and troubleshooting methods across all IndraMotion-based systems saves time in installing, training, and maintaining Rexroth-based systems.
MANAGING THE EXECUTION OF CONTROL
Proficy Assembly from GE Fanuc Automation, Inc. (Albany, NY; www.gefanuc.com/en/Industries/Automotive/index.html) for Tier 0.5/1 automotive suppliers is basically a manufacturing execution system (MES) with lean manufacturing components and other built-in capabilities. For instance, in-line sequencing, which responds to OEM broadcasts, releases orders into production and to subassembly feeder lines. Option build data is generated at individual assembly stations. Error proofing capabilities include displaying process steps to the operator; activating pick-to-light; torque control devices, materials handling equipment, and other devices for the operator; and, through appropriate manual, semi-automatic, and automatic feedback, confirming the operator's following of those process steps. Product reporting provides canned reports by line, station, step, and takt time, as well as sending relevant alerts about production. Proficy Assembly will also generate product birth certificates that include the details of each order, its bill of materials (BOM), component serial numbers, process steps and key parameters about production, quality inspections, and any alerts during production.
Here's the kicker, explains Rich Breuning, director of discrete market development for GE Fanuc. OEMs and Tier 1 manufacturer might typically spend millions of dollars for an MES--homegrown or third-party purchase. Instead, turnkey installation of Proficy Assembly is $250,000 per production line (figure 40 to 50 stations). Deployment is expected to take less than six weeks. Typically, such production lines have a PLC for conveyor control with some rudimentary interfaces to pick-to-light bins and some error-proofing equipment, continues Breuning. The PLC remains, but it gets its "marching" orders from Proficy Assembly running on a Dell server. In the very near future, adds Jack Faett, GE Fanuc's director of discrete OEM solutions, the MES will run inside a GE PACSystem server, a controller with a single board computer (SBC). (Points out Faett, there are SBCs just as powerful, if not more powerful, than desktop servers.) The SBC can be put inside an industrialized PC or be part of a VME rack system.
Assembly Application Suite (AAS), also from GE Fanuc, is similar to IndraMotion from Bosch Rexroth. AAS integrates hardware and software into predefined control and HMI subsystems. In particular, AAS consists of Proficy Machine Edition LD-PLC and HMI "building blocks" for developing assembly systems. These building blocks follow commonly defined areas used in developing assembly applications: zone (master) controllers, automatic stations, manual stations, repair stations, and test stations. AAS recognizes a wide variety of hardware devices, including GE Fanuc Panel C industrial computers, Quickpanel, PACSystems, I/O digital servo motion, Profibus fieldbus, and radio frequency identification (RFID) products.
Templates of screens, logic, and data are all part of the AAS package, along with HMI, fieldbus I/O, axis management, RFID, and support for third-party devices. Templates are based on structured function blocks programmed in ladder code; users need only drag-and-drop these function blocks for processes like I/O manipulation, motion, and RFID management. The templates are based on symbolic variable objects common to PLC and HMI. Everything that's done in the HMI is done with a name variable and exported to the controller. The controller then figures out where to put the variable. As a result, the user doesn't have to maintain a memory map or fixed addressing. In addition, the resulting assembly line applications are written in such a way so that the variables needed by GE Fanuc's MES are readily available for annunciation, data logging, and other MES activities.
In the past, control systems were on their own. They operated on dedicated, proprietary networks, or they were on standalone machines. Security was quite localized. Now, "everything is 'Ethernetted,'" says Cindy Hollenbeck, vice president of SoftPLC (Spicewood, TX; www.softplc.com and, for firewall products, www.gatecraft.net). Such integration comes at a cost in security. In automotive production, especially, all sorts of people--machine and control suppliers, maintenance services, plus the OEM's and Tier X's own engineering, production, and accounting staffs--around the plant accessing those Ethernet networks, viewing data, fixing and changing things. Then there are people outside the plant. Integrators often access their client's control networks through virtual private network (VPN) tunnels dedicated for supplier/customer electronic communications. Once on a VPN, the integrator can go everywhere within the client's network.
In the traditional IT world, the focus has always been on protecting the server, the computer that runs the programs and both collects and disseminates data. This was fine in office applications because if the server is protected, it's a relatively minor matter if a client workstation goes down. However, in the industrial world, the client is a PLC, a drive, a SCADA package. Says Hollenbeck, "If a client goes down, bad things could happen. Somebody's arm could get cut off. The whole notion of industrial security needs to be looked at differently than office security." Toward that end, SoftPLC has embedded a firewall into its PC-based controls. There are four firewall products that provide hardware-based network security for VPN and industrial networks, as well as for cable modem and wireless access points. Again, the idea is to protect the nodes, not the server. (Note that SoftPLC is not relying on the firewall that comes with the Microsoft Windows XP operating system or even third-party firewalls for Windows 2000 or XP. There's a good reason for that: The PC-based controllers from SoftPLC runs on embedded Linux.)
Of course, no firewall can stop the person who wants to be malicious. But for normal operations, the firewall permits controller access to those who need it, while preventing, for example, OEM #2 from going into OEM #1's machine. With SoftPLC's embedded firewall, outsiders can use VPN to access specific PLCs, as opposed to the entire network. This approach provides much tighter security requiring fewer rules to set up than a traditional firewall, claims Hollenbeck.
By Lawrence S. Gould, Contributing Editor
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|Title Annotation:||DIGITAL DOMAIN|
|Author:||Gould, Lawrence S.|
|Publication:||Automotive Design & Production|
|Date:||Dec 1, 2006|
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