Machines chat on-line

Motionsystemdesign Com Engineering Basics Factory Floor

In many ways, digital-based technology has been a boon to motion engineers. It’s simplified much of the grunt work of system setup and tuning. It’s also allowed engineers to design machine tools and equipment that can execute more complex tasks faster, with tighter accuracies and higher efficiencies.

It’s also raised expectations. When a customer insists on a design change in mid-production, the response better be: “No problem.” When a shipping deadline gets pushed up, manufacturing processes must likewise adapt. To make the necessary adjustments, engineers need access to information about machine and plant operations - whether they’re on the plant floor, in a field office, at home, or in a meeting with the boss.

Fortunately, the communication network to tap such information is already available. It’s called the World Wide Web. With a Web browser, and integrated webserver technology, engineers now have control over machines plus communications.

Making the connection

Efficient sharing of production data across an organization requires a network. However, many networks are proprietary and, as such, useful only within the company that developed them. Other networks claim openness, but their ability to share information among devices and other networks more often hinders rather than aids effective data sharing.

The leading network for the Webenabled factory is the Internet. And when used with the World Wide Web - the networked hypertext system invented in 1990 by Tim Berners- Lee at the European Center for Nuclear Research (CERN) - information can move across a diverse range of platforms near and far. Through these communication tools, engineers can check production rates, diagnose equipment problems, measure quality levels, set up maintenance, and obtain scheduling information, almost anywhere.

The Internet uses TCP/IP over Ethernet-based media. The hardware implementing these protocols is readily available and inexpensive.

One of the major benefits of the Web is that engineers don’t have to waste time or money developing a company-standard operator interface. The best interface, for remote as well as local displays, is one of the popular Web browsers such as Netscape or Microsoft Internet Explorer. They are available at minimal cost. In addition, training on how to use one is low.

Connecting any plant device to the Internet is fairly simple. Most devices link to PCs through cabling. The PCs, in turn, function as Web servers and connect to the Internet.

Motion controllers, though, can use a network communications module with embedded webserver technology. Java applets and ActiveX components offer a direct and dynamic way to incorporate interfaces that connect to plant information systems.

Beyond control

In addition to providing motion and machine control, controllers with integrated webserver technology can store operational information, presenting it on Web pages. credentials and a Web browser can view these pages over the Internet.

Data can be continuously updated, so that the system displays the latest information. In this way, motion information can be accessed and processes validated from anywhere in the world at any time of day.

Such storage capability also makes it easier to access operator manuals and user guides. Documentation may be stored on a controller and downloaded as needed. Revisions can be made with the press of a button, giving users instant access to the latest information, and reducing the cost and time of reprinting.

Today’s production machines with controllers as proxies, can fully participate in plant-wide networks. In their new role, machines may be called upon, for example, to provide operating efficiency reports for plant management, reliability data for quality assurance, uptime and downtime records for OEMs and design team members, service and maintenance information for technicians, production data for customers and suppliers, and delivery information for sales and marketing. With this sort of information access, engineers can make all the adjustments they want and immediately gage the effect.

Shaping of the future

The networked factory is taking the enterprise global and making distance and time irrelevant for managing plant affairs. Communication is no longer at the mercy of time zones. Web-enabled controllers collect and communicate information through the Internet to any location at any time.

With the proper security permissions, service personnel can diagnose machine operations, reprogram procedures, and restart machines from any locale. This permits rapid process correction, enabling engineers to take steps before a problem seriously affects product quality and yield. In addition, companies save on travel and lodging expenses.

And armed with timely information, an empowered work force is better able to meet customer needs through anticipation, rather than reaction.

Tom Schermerhorn is vice president, Systems Group, Control Technology Corp., Hopkinton, Mass.

Secure the network!

Network security isn’t simply a matter of installing a firewall. System architecture, practices, and policies all bear on how easy or difficult it is for others to gain unauthorized access to your data. Thus, when designing your plant network, keep these factors in mind.

Isolate and control traffic flow.
Use routers and Ethernet switches instead of bridges and hubs. This will not only result in a less congested network, it will also restrict data to only the necessary Ethernet segments controlling exchange. This, in turn, minimizes the opportunity for network “sniffers” to capture sensitive data, such as passwords. Sniffers are surreptitious programs that force a computer’s network interface to send them every packet of data that appears on the network.

Minimize points of access.
Technologies such as Microsoft’s Point-to-Point Tunneling Protocol (PPTP) and Layer 2 Tunneling Protocol (L2TP) are coming into use, allowing secure remote access to plant networks. Reducing the number of such external access points makes security management a simpler task.

Examine physical security exposure.
Network security should be part of conventional plant security. If someone could walk in off the street and steal a computer, or connect a wireless bridge to your network, then the most secure firewall in the world won’t help you.

Establish secure authentication practices.
Use only encrypted authentication methods, such as CHAP (or MS-CHAP) or Kerberos, and establish policies for appropriate passwords. Change passwords often.

Consider personnel issues.
When personnel change, take steps to ensure that passwords are changed and accounts terminated promptly.

Encrypt your data.
Particularly for traffic leaving the facility, it is a good practice to use technologies that support encryption, such as PPTP, to frustrate attempts to monitor your network traffic.

Maintain internal and external awareness.
Review system logs regularly for abnormalities. A break-in attempt often requires several sessions, and early attempts may leave telltale “footprints.” Also, monitor web resources such as the Computer Emergency Response Team Coordination Center (CERT/CC) which reports on network security issues and known vulnerabilities. Their Web address is www.cert.org.