Control Engineering Control Components eNewsletter for August 2002

By Jim Montague August 20, 2002

In this issue:

U.S. insulated wire and cable market to exceed $26 billion by 2006
Sensors Expo moves to Boston for Sept. 24-26
Product Focus: discrete sensors provide a lot of bang for the buck
Back to Basics: a primer on safety controllers

Digital relays improve power stability, control and safety for Marathon Oil
Axcess’ sensor and alert system enables wireless sensing
TI launches low-power, zero-drift amplifiers for precision signal conditioning
CE plans webcasts for October on manufacturing productivity

U.S. insulated wire and cable market to exceed $26 billion by 2006

Demand for insulated wire and cable in the U.S. is expected to increase 5.1% per year through 2006 to more than $26 billion, according to a recent study, Insulated Wire & Cable, by the Freedonia Group Inc. (Cleveland, OH). Though well below the robust gains made during most of the 1990s, projected growth for the insulated wire and cable market could represent a significant improvement in the market’s performance over the past three years, which Freedonia reports were hindered by weakness in technology-related capital investment.

U.S. Insulated Wire and Cable Demand(in millions of $)

% annual growth

% annual growth

2001 to 2006








Source: Control Engineering with data from Freedonia Inc. (Cleveland, OH),

The study found that the best growth prospects will be for high-end products, such as fiber-optic, coaxial and multi-conductor wire and cable. Motor vehicle wire is also expected to achieve improved gains because of an improved outlook for U.S. light vehicle production. However, these gains for the wire and cable industry will be dampened by what Freedonia calls a difficult pricing environment. This reportedly is caused by the fact that wire and cable are increasingly viewed as commodity items.

The main growth-restraining factor for fiber-optic cable will be eliminating the capacity glut that occurred when fiber-optic networks were overbuilt in 1999 and 2000. This will take more time to alleviate, though cable demand is expected to recover and begin to grow more quickly as demand for high-speed data services expands with greater availability.

The study also found that international trade will continue to play a major role in the insulated wire and cable field with import and exports each comprising more than 20% of total shipments. Export opportunities will be best for more advanced products, such as fiber-optic cable, because these products will be increasingly used in construction of telecommunication networks in developing nations. Despite an overall trade surplus, the U.S. will continue to run a significant deficit in some insulated wire and cable product categories, such as telephone and remote vehicle wire.

Communication will continue to be the largest market for wire and cable, mainly because this field includes so many applications. Though gains will exceed the overall industry average, decelerating growth in capital investment by telecommunications suppliers will cause gains to slow from the pace of the 1990s. Communications and information processing are expected to achieve the fastest growth of any markets, due to continuing increases in computer networking. Increasing production in the automotive industry will also create opportunities, as will growth in the amount of electronics contained in vehicles produced in the U.S.

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Sensors Expo moves to Boston for Sept. 24-26

The second of this year’s two Sensors Expo show will be held Sept. 24-26 at Boston’s World Trade Center West. Organizers say the event will bring together a broad range of technologies that are shaping sensing, micro-electromechanical systems (MEMS), data acquisition, control, and communications.

For instance, the Exhibit Hall will feature technologies and solutions from more than 140 companies, and will give visitors a chance to talk one-on-one with the innovators who make those products. Plus, a European Pavilion will feature products not found in North America.

Meanwhile, the show’s Technical Conference, which runs Sept. 23-26, will include about 100 speakers and panelists, presenting the latest advances in sensor technology and design for engineers, scientists and managers. Sessions will cover biosensors and bioMEMS; data acquisition and analysis; intelligent systems and smart sensors; nanotechnology and MEMS; wireless and tethered communications; and enabling technologies, including Internet, networking, and embedded technology.

Sensors Expo’s keynote will be presented Sept. 24 by Ray Kurzweil. He will speak about ‘The Rapidly Shrinking Sensor: an Intimate Merger with Our Bodies and Brains.’

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Product Focus: discrete sensors provide a lot of bang for the buck

Once upon a time, the term discrete sensor was synonymous with limit switches, but not anymore. Today’s discrete sensors are intelligent, rugged, accurately measure or sense many different things, provide all sorts of built-in protection, know how to communicate on a network, and still don’t cost a lot of money.

Reed Research invited a group of Control Engineering subscribers during February 2002 to participate in an online survey about discrete sensors. Responses were received from 434 subscribers. Survey results are based on the 386 respondents involved in the specification, recommendation, and/or purchase of discrete sensors. Among those specifying, recommending, and/or purchasing discrete sensors, 60% do so for in-plant requirements, 23% purchase for original equipment manufacturer (OEM) needs, and 18% purchase for both in-plant and OEM requirements.

Discrete sensors are used in a wide variety of applications, including:


Fill-level (liquid)

Raw-material processing

Fill-level (solids/powders)


Plastic product manufacturing

Fabricated metals


Web-based products


The survey also asked respondents to indicate the most used discrete sensor type, current and future. Not too surprising, limit switches are the current most used (97%), followed closely by safety switches (93%)

Photoelectric sensor packaging preferences were also among the survey questions. Survey respondents indicate significant use of four packaging options: limit switch (65%), cylindrical (60%), miniature (59%) and fiber optic (53%).

Looking back at previous discrete sensor studies, characteristics of corrosion resistance, wash-down protection, alignment/set-up aid and short-circuit protection consistently rank highest in importance to survey respondents. However, weld-field immunity has nearly doubled in importance between 1998 and 2002.

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For manufacturers of these products, visit the Control Engineering Buyers Guide at /buyersguide

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Back to Basics: a primer on safety controllers

Interest in providing safer workplaces is clearly growing among machinery manufacturers and end-users. This concern is stimulated by increasing awareness of the benefits of safer work environments, and by new and emerging safety standards and guidelines, such as the European Machinery Directive, ANSI B11.19, ANSI B11.20, ANSI/RIA 15.06 and OSHA National Emphasis Programs. Increasing interest is also shown by growing use of ‘safety-approved’ machine guarding components, as well as greater awareness of the importance of risk assessment by equipment designers and end-users, according to Maurizio Lauria, application engineer, Schmersal Inc. (Elmsford, NY).

‘Professionals involved in workplace protection and machine guarding have been influenced by a growing body of standards and regulations,’ says Mr. Lauria. ‘In particular, decision-tree models, such as EN 954, and the recent publication of ANSI’s risk assessment guidelines, ANSI Technical Report B11.TR3, have prompted OEMs and end-users to recognize the importance of ensuring reliable operation of safety circuits via fault monitoring and detection by `safety controllers.’ ‘

Defining safety controllers

Mr. Lauria explains that safety controllers are electromechanical or microprocessor-based monitoring devices installed between machine-guarding input devices and the machine’s primary stop controls, such as motor contactors or control relays. These controllers typically contain redundant, self-checking, safety system monitoring circuits and positive-guided output relays, commonly called ‘safety relays.’ Each controller is designed to detect faults in the safety circuit’s components and interconnection wiring, as well as in its own internal monitoring circuits and output relays. Also, it senses actuation of a machine guard interlock/e-stop switch.

‘If the controller detects a fault or open machine guard, it disables the output signals; stops the machine; and/or keeps it from restarting until the fault is corrected,’ says Mr. Lauria. ‘Units are available for use with machine guard interlocks, coded-magnet sensors, safety edges, safety limit switches, two-hand controls, light curtains, e-stops, emergency cable-pull switches, safety mats, and laser scanners, which satisfies a broad range of Stop Category 0/1 application requirements.’

Detecting faults in safety circuits

Depending on how they’re designed, Mr. Lauria adds that safety controllers are capable of detecting various types of faults that may compromise the performance of the safety circuit. These include:

Welded or stuck interlock/e-stop switch contacts

Misaligned guards

Open circuit in interconnection wiring

Short circuit in interconnection wiring

Short-to-ground faults in interconnection wiring

Fault in the controller’s monitoring circuits

Welded or stuck contacts in the controller’s safety relays

Insufficient operating voltage to the controller

Capacitive/inductive interference on the controller’s inputs

Welded or stuck contacts in the controlled primary machine stop element, such as a positive-guided motor contactor or control relay.

‘Some microprocessor-based safety controllers also feature integrated system diagnostics with LED displays, which indicate fault type and location to speed up troubleshooting and minimize machine downtime,’ concludes Mr. Lauria. ‘Ensuring that a safety system will perform requires ability to detect safety circuit/component faults, then shut down the machine until the fault has been corrected. Safety controllers heighten safety system reliability and reduce the possibility of worker injury.’

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Digital relays improve power stability, control and safety for Marathon Oil

To improve power stability, enhance control and safety, eliminate costly shutdowns, and increase operational knowledge, Marathon Oil recently implemented SEL-351 digital protective relays from Schweitzer Engineering Laboratories Inc. (Franklin, Tenn.) at its Indian Basin (Lakewood, N.M.) and Yates Field (Iraan, Tex.) natural gas plants.

Charlie Adams, Marathon’s senior engineer, says the Yates plant is a support facility for the Yates oil field, serving as a large compressor station that recycles gas for injection into the reservoir. Self-contained sets of generators prevent offline trips from stopping the plant, but even a short power shutdown poses the risk of losing control of plant processes in which chemical and cryogenic processes within the plant go ‘off spec.’ Mr. Adams says it could cost $15,000 in commercially purchased fuel alone to restart the Yates facility, and an extended power outage could dent Yates’ daily 20,000-barrel production.

Similarly, with a daily production of 259 million cubic feet of natural gas, Indian Basin could lose $30,000 per hour and face fixed startup costs of $100,000 if a severe power shutdown occurred.

`Trip index’ aids reliability

To increase reliability at the Yates plant, Mr. Adams focused on the breaker trip frequency of the utility feeders that tie into the bus, where they had a utility tie and two generator sets feeding power into the bus. ‘We refer to this frequency as the trip index,’ he says.

Previous records showed 1,000 trips on the utility tiebreaker in just three years, or about one per day, a figure that Mr. Adams says had to be brought down. Yates also had a messy, overlapping combination of generator control and governor control problems, reverse power trips, significant transient issues, and unreliable electromechanical relays with questionable maintenance histories.

Following an evaluation process that included input from Yates’ local power supplier, Mr. Adams and his team opted to replace unreliable relays on the plant’s utility feeders with SEL-351 digital relays; install two SEL-300G generator relays; and replace 34 aging electromechanical relays with other new SEL hardware. Retrofit of the 12.5-KV switchgear at Yates had to occur within a rigid one-week shutdown window.

The ultimate measure of the project’s success was an immediate four-fold improvement in the trip index. When the power system was brought back up, the trip index factor decreased from nearly 1.0 to about 0.25. Mr. Adams says the plant’s new SEL-351 relays were the biggest contributors to this victory.

The team also started collecting data that allowed them to find the root causes of plant problems, and find out if trouble was occurring on the supply side or demand side. ‘Finally having legitimate data collection and reporting lets us focus on smart fixes. We’ve even brought data to the utility that helped us solve problems on their side of the system,’ he says. Mr. Adams also uses SEL’s remote access and monitoring capabilities to configure devices and access surveillance reports, typically calling the relays twice a day to check status and look at the triggers and histories for ‘smoking guns.’

Following the Yates project, Mr. Adams was called to the Indian Basin plant, which has a more complicated power system consisting of a 480-V bus, three turbine generators, a utility connection, and a standby feeder. The new challenge was to integrate two additional distributed generators and a 900-hp motor, which both feed into and draw startup power from the bus. Indian Basin also had many of the same problems as Yates, including phantom trips and fluttering generator controls.

Following another evaluation, an SEL-351 was installed on Indian Basin’s utility feeder, though the generator relays and other aging hardware was not replaced. Later, an additional SEL-351 relay was added to Indian Basin’s bus. Mr. Adams adds that he is currently pitching a retrofit of Indian Basin’s generator relays.

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Axcess’ sensor and alert system enables wireless sensing

Axcess Inc. (Dallas, TX) unveiled Aug. 13 a wallet-sized device, selling for less than $20, that can turn standard alarms, biosensors and chemical sensors into wireless sentries, capable of sending alerts over landline or wireless systems. The company says its device will enable rapid, economical deployment of pervasive sensor networks, which was a key need highlighted in a recent National Research Council Report on Counter-Terrorism.

‘We’ve broken the cost barriers that stood in the way of broader deployment of wireless technology, and opened a new era for sensor-based security systems,’ says Allan Griebenow, Axcess’ ceo. ‘Once you do away with wiring, you can install a lot quicker, and design systems with sensors in places that were previously cost prohibitive.’

The new device, Universal Sensing Appliance (USA), attaches to any sensor with an electronic interface. It interprets the sensor’s data, and wirelessly transmits to network servers. The event is recorded; a response is generated; and alerts are broadcast immediately. The USA wireless unit can also enhance the utility of sensors and systems that monitor occupational safety and manufacturing processes.

Axcess adds that USA is part of an overall system that brings together all of its technologies, including active, battery-powered radio frequency identification (RFID), networked digital video and integrated browser-based software. It can accommodate many commercial and industrial sensors, and immediately identify, transmit, record, alert and notify users about safety violations, security breaches and potential terrorist threats.

‘The complete end-to-end solution includes gathering and interpreting sensor data; transmitting it using wireless technology; and then networking the information over the LAN or Internet to wherever it’s needed. This information can be presented in any fashion desired by the end-user, including custom-based alarm criteria that triggers instantaneous alert messages over the network,’ says Wayne Steeves, Axcess’ RFID engineering vp.

The entire system owes its flexibility to Onlinesupervisor browser-based software. Users can customize the dashboard display to show data in which they’re particularly interested. Raw transaction data is available, along with user-defined alerts, and these can be investigated in greater detail. For alerts with video surveillance, both recorded video events and live video of the area are directly linked for immediate review. The user can also define the list of recipients for e-mail or pager alerts.

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TI launches low-power, zero-drift amplifiers for precision signal conditioning

Texas Instruments Inc. (TI, Tucson, AZ) recently announced that its Burr-Brown product line now includes what it reports are the industry’s lowest-power, zero-drift operational amplifiers. TI adds these amplifiers are ideal for precision, power-sensitive applications, such as handheld test equipment, medical instrumentation, temperature measurement, transducer signal amplification, electronic scales, automotive systems and battery-powered instruments.

‘OPA334 and OPA335 provide customers with the ultimate cost-effective solution for precision signal conditioning and reinforce TI’s leadership position in the low-power, low-voltage market,’ says Tadija Janjic, strategic marketing engineer of TI’s high-performance amplifier products. ‘By offering a three-times reduction in quiescent current, these devices enable customers to achieve higher precision designs while reducing power consumption.’

OPA334 and OPA335 op amps are available in micro-size SOT23 packages and feature low-quiescent current (300 uA); single-supply operation; and rail-to-rail output swing within 10 mV of the rails. The devices use auto-zeroing techniques to provide ultra-low offset voltage (1 uV typical) and near-zero drift over time and temperature (0.02 uV/C).

OPA334 family includes a shutdown mode allowing the OPA334 to be switched from normal operation to a standby current that is less than 1uA. OPA334 and OPA335 operate on single or dual supplies as low as +2.7 V (+/-1.35 V) and up to +5.5 V (+/-2.75 V). All versions are specified from -40C to +125C.

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CE plans webcasts for October on manufacturing productivity

Control Engineering will conduct two webcasts in October on how automation tools boost productivity. The two online events will be moderated by Mark T. Hoske, Control Engineering’s editor-in-chief.

The first webcast, ‘Standard roadmap to manufacturing productivity,’ will show how the OPC Foundation (Scottsdale, AZ) improves manufacturing by delivering non-proprietary technical specifications-essentially a common roadmap to productivity. Getting participants to agree on the best course hasn’t always been easy, but results benefit end-users. Efforts now extend into Ethernet to ensure interoperability advantages continue among automation/control applications, field systems/devices, and business/office applications. The speaker will be Tom Burke, OPC Foundation’s president and advisory software developer at Rockwell Automation.

The second webcast, ‘Everything you need to know on one screen,’ asks if the ultimate productivity tool has arrived. A broad class of software shows key performance indicators for manufacturing, design, sales, logistics or whatever needs monitoring. This ‘digital dashboard,’ basically a human-machine interface on steroids, can be rapidly customized to fit users needs and changing business goals. Panelists will show how to get the most from this software. Panelists include Jamie Bohan, business manager for Honeywell Industry Solutions’ Uniformance product line; Kevin Roach, global solutions vp for GE Fanuc, part of GE Industrial Systems; and a representative from the Manufacturing Industry, Industry Solutions Group (ISG) at Microsoft Corp.

Other presentations will include speakers from IBM, Segway, Unilever, Microsoft, 3M, JC Penney, and Amana. The webcasts are part of SupplyChainLinkExpo, a free online conference and tradeshow on Oct. 16-17.

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