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Articles from 2005 In May


Unique Ring Motor for DARPA Unmanned Vehicles

A high-efficiency brushless ring motor based on patented electromotive coil technology is reducing energy consumption and increasing operational time for DARPA Unmanned Vehicles. For ground and underwater vehicles, the ring motor can eliminate transmissions, allow larger payloads, and provide an ability to move faster, farther or longer between battery charges.

Ring Motor Technology
The brushless ring motor (TG8250) developed by ThinGap Corporation (www.thingap.com) under DARPA contract is in development for a variety of air (UAV), ground (UGV) and underwater (UUV) applications. The motor delivers 1.5 hp continuous per pound and provides a form-fitting platform that the company claims is quieter than previous designs, conserves battery power and provides a gyroscopic effect that reduces vibration and stabilizes the UAV.

"The motor looks like a steel ring with an outside diameter of 8.25 inches, coupled to an iron, inner ring, with an inside diameter of 7.5 inches and height of 1.4 inches,"  says Greg Graham, chief technology officer for ThinGap. "A copper centered ring forms the stator which sits inside the iron rings.""In fact, it doesn’t look like a motor with its large open inner diameter surrounded by the 0.374 inch thick ring that makes the motor," says Graham. "The shape of the ring motor is part of what makes it a solution for ducted-fan, direct wheel and screw drive propulsion."In ducted-fan applications, Graham says that the blades fit within the inside diameter of the ring motor and the outer ring becomes the rotating member over which nacelles or composite structures can shield the mechanics of the outer ring. With its large diameter ring, the motor creates its own gyroscopic effect stabilizing the craft similar to the rotors of a helicopter in flight. The stator and rotor's magnetic fields create a fixed path at the centerline of rotation.Offsetting the rotor magnetic field from its path within the stator magnetic field creates a magnetic force that resists the offset. Graham says this increases stability, allowing UAV's to fly during rough weather conditions and to dampen vibration and improve imaging capabilities.

Unique Technology
The ring motor is fundamentally different from a conventional DC brushless motor in two areas:  the coil and rotating parts of the motor. The ring motor coil (stator) replaces wire windings with precision-machined copper sheets formed into a circular coil, allowing a higher copper-packing density than copper wire. The coil assembly is a free-standing coil structure without supporting laminations.

 
Ring Motor with rendering of fan blades developed by ThinGap for use in unmanned vehicles.

By winding the coils in parallel or in series, the stator assembly can be operated at 50V to 280V or at three different torque constants. At 72V, the motor operates at 75% efficiency, for motor and controller with all 4x coils in series, and provides shaft output power of 1,200W. With quadruple redundancy, if one coil fails, the motor continues to operate. And since iron is not used in the coil, Graham says the magnetic field does not affect inertia, reduces rotational losses, (eddy currents in the laminations) and allows the non-operating coil to freewheel like auto-rotating helicopter blades.

Different Applications
Under the latest DARPA contract, a larger motor is being designed to develop 6.5 hp constant output from 500 rpm to 5600 rpm to match the requirements of a UGV. Graham says that the speed torque curve of the motor suggests that optimized output will reach 40 hp or 30Kw output. For UGV applications, the motor will deliver enough peak and high torque at low speed to eliminate gearboxes and drive trains in smaller vehicles, although larger vehicles will still use a gearbox.

Graham claims that by eliminating the magnetic detent, the motors will deliver very smooth and cogging-free rotation, even at slow speeds. The ring motor is also envisioned to mount directly to the wheel, improving control and maneuverability.

 
Cross-section of mating rotor ring assembly consists of a U-shaped iron channel with a thin wall and magnets, mounted to the inside of the outer steel ring.

For more information, visit www.thingap.com.

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Titanium Welding Code Creeps Ahead at AWS

A much-anticipated welding code expected to aid designers and spur the use of titanium in industrial and military applications outside of the aerospace sector continues to make steady progress towards final approval.

Now in its eighth draft, the D1.9 Structural Welding Code--Titanium was submitted in late May to the American Welding Society’s (AWS), Structural Welding Committee. From there it will go to the Miami-based AWS’s Technical Activities Committee (TAC), composed of 40 members representing a broad cross section of the U.S. welding industry.John Gayler, AWS senior staff engineer, described the code as a document whose publication will follow the rigorous approval guidelines of the American National Standards Institute (ANSI), Washington. It’s expected that AWS approval of the code will come in late 2006 or early 2007--possibly sooner. Once finalized by AWS, the code will be submitted to ANSI for publication.The code will define minimum requirements for welding titanium in structural applications. It is a methodology that includes an introduction, a design section covering static and cyclic loading,  details on fabrication, assembly, inspection and welding procedures, and a series of final commentaries. It also will include a mandatory ballistic annex, providing specific data offering weld specifications for titanium vehicle structures subject to potential ballistic threats during combat operations.John Lawmon, principal engineer at Edison Welding Institute (EWI), Columbus, OH, said new business opportunities to design and develop titanium parts for structural/architectural and military vehicular applications are spurring the effort to draft the code.The Army's requirements to produce lighter, more deployable systems is a key factor in its use of titanium and the development of a structural welding code, explained Stephen Luckowski, chief, prototype manufacturing team for the Army Armament Research, Development and Engineering Center (ARDEC), Picatinny Arsenal, NJ. Luckowski serves as the chairman of the AWS’s D1N subcommittee on titanium structures.Lawmon, the vice chairman of the D1N subcommittee, said that, once finalized, the code will define critical areas of concern to design engineers, like weld fatigue. Lawmon said that while fatigue is well documented for welded titanium components used in the aerospace industry, there is very little information available in the public domain for construction applications like roofs and facades or structural parts for military ground vehicles.John Monsees, president of Hi-Tech Welding & Forming Inc., El Chajon, CA (near San Diego), said that “what’s needed is a definitive document specifically written for titanium welding to build structural components,” noting that aerospace specifications are difficult to translate for these applications. “There (currently) isn’t a good book to go to teach best practices for welding titanium in structural applications.”Monsees, also a member of the AWS committee, said that, given its light weight, high strength and corrosion resistance, titanium is a “natural choice” for military ground-based vehicles as well as Navy programs like the DDX destroyer and the CVN-21 aircraft carrier. “But (engineers and manufacturers) need welding specifications to design and build titanium systems for these projects,” he said.

 
Road tanker made from titanium. Photo credit: EWI

For designers, the code will provide a consistent engineering language for utilizing titanium in structural applications. It would accelerate the development process and help inspire improved manufacturing techniques and part designs, which could more fully exploit the high strength-to-weight ratio of titanium.For titanium suppliers and fabricators, the code could help move the metal into new, lucrative industrial programs. It has long been the dream of titanium producers--who historically have sought to minimize titanium’s cost penalty when compared with steel or aluminum--to diversify from aerospace programs into higher volume applications.Perhaps the most revealing and useful section of the code is the final commentaries, according to Lawmon. This section will provide engineers with insights and background information on issues such as guidance for weld inspection and how to develop data for special part geometries, he said.“These are areas that design engineers will need to think about twice when specifying titanium,” he said. The commentaries also will help designers “read in between the lines” of the code.“Don’t assume the code will solve all application problems,” Lawmon cautioned. “Designers need to think about weld joint details, but they also will need to think about the overall manufacturing process.”It’s expected the welding code also will promote the use of automated manufacturing systems as a way to further reduce costs and enhance part quality and repeatability. As a parallel effort to support this thrust, EWI has embarked on two research programs. The first program seeks to increase the weld deposition rate and quality of gas metal arc welding (GMAW), also known as metal inert gas (MIG) welding, making it at least three times faster than the gas tungsten arc welding (GTAW) process, also known as tungsten inert gas (TIG) welding, by designing pulse-welding parameters for reduced spatter at low current levels.The second program will look to extend the life of the contact tip in the MIG welding process. Lawmon said the goal is to make MIG more suitable for extended duty cycles in high-volume manufacturing.


Welding Wisdom: Keep It Shielded, Keep It CleanMonsees, who leads Hi-Tech Welding & Forming, an 80,000-square-foot manufacturing facility with 55 workers, has been contracted by the International Titanium Associations (ITA), Broomfield, CO, to teach a titanium welding seminar at the ITA’s annual conference, which will be held at the Marriott Camelback Inn, Scottsdale, AZ, Sept. 25 to 27.Welding is widely considered to be the key skill set among titanium fabricators, enabling a manufacturer to distinguish itself from competitors. Titanium, highly reactive compared with most metals, must be shielded with inert gases at all times during welding as it readily oxidizes. This protection must be extended to include the hot base metal, the cooling weld bead and the molten puddle. Without this shielding, the result can be cracking and diminished mechanical properties of the part.Offering advice to engineers and manufacturers, Monsees said that, in addition to inert-gas shielding, cleanliness is the watchword when it comes to welding titanium. Using the example of TIG welding, he said this focus on cleanliness includes frequent wire brushing of the base metal using a stainless steel brush designated for titanium only, the use of ultra-high purity argon gas, and the use of high-purity acetone for cleaning the titanium surfaces to be welded and welding filler wire.Maintaining such a clean regimen enables manufacturers to avoid problems such as porosity and a loss of toughness typically associated with improper titanium welding, he said.

Three-Axis Accelerometers

Three-axis silicon-based accelerometers have been gaining momentum for the past 18 months, as equipment manufacturers have begun employing them on applications ranging from washing machines to cell phones to laptop computers.

The fingernail-sized sensors, which detect z-axis motion along with the traditional x- and y-axis motion, are enabling products to perform functions that would have been difficult or impossible before. Hard drive manufacturers, for example, have begun incorporating the devices as a means of detecting free fall. Using the z-axis sensing capability, a hard drive can "know" when it is falling and, as a result, place itself into a "park" mode to prevent data from being lost on impact.

"That could have been done before, but it would have taken two sensors to do it," notes Bob Tucker, operations manager for sensor solutions at Freescale Semiconductor, one of several companies producing the MEMS (micro-electromechanical systems) silicon sensors.

Kionix, Oki, MemSense, Hitachi, and STMicroelectronics have also placed products on the market, and Analog Devices will roll out a three-axis product later this year.

Web Resources
//Check out these companies, which also offer three-axis sensors//
Hitachi Metals America's three-axis accelerometer:
http://rbi.ims.ca/4391-537
Memsense's three-axis nIMU (nano-IMU):
http://rbi.ims.ca/4391-538
 
 

Freescale's MMA7260Q

Freescale Semiconductor's new three-axis sensor, rolled out on May 11, is the newest three-axis MEMS device and the first to include a "g-select" feature that allows engineers to program it to detect a prescribed force range. Freescale's device also boasts exceptionally low current draw: 500 µA normally; and 5 µA in a power save mode. The device resides in a 16-lead, 6-mm × 6-mm × 1.45-mm package.
For more information on Freescale's three-axis sensor, go to www.freescale.com.

 

Oki Electric's ML8950

Oki Electric Industry's tri-axis sensor measures just 5 mm × 5 mm × 1.4 mm, and incorporates built-in amplifiers and A/D converters, resulting in a serial digital output that can be directly connected to a CPU. In addition to detecting tri-axis acceleration, the ML8950 can also detect inclination and impact shock, as well as measure degree of vibration.
For more information on Oki's three-axis sensor, go to http://rbi.ims.ca/4391-534.

 

Kionix's KXP74

Kionix's new device is said to be the thinnest tri-axis sensor available, measuring a scant 1.2 mm thick and 5 mm × 5 mm square. Kionix representatives say that the product's real strength, however, lies in its low-noise performance, which makes it well suited for applications such as precision compass tilt correction. A Serial Peripheral Interface (SPI) also eliminates the need for an analog-to-digital (A/D) converter, thus reducing system component requirements.
For more information on Kionix's three-axis sensor, go to http://rbi.ims.ca/4391-535.

 

STMicroelectronics' LIS3L02

STMicro's three-axis product line combines a MEMS-based sensor and interface chip in a single package. The company's three versions of the technology include one that produces an analog output, another that provides an analog voltage and PWM output, and a third that produces a serial digital output. During transport, the devices can withstand accelerations up to 1,500g, making them sufficiently shock resistant for mobile phone applications.
For more information on STMicroelectronics's three-axis sensors, go to http://rbi.ims.ca/4391-536.

Demo Kit Simplifies ZigBee Applications

With the ZigBee protocol officially approved in the first quarter of 2005, Microchip's PICDEM™ Z ZigBee demonstration kit provides a timely means of starting a new design. The kit includes two motherboards, two 2.4 GHz RF cards, and a CD containing the ZigBee protocol software and a PCB layout database. In addition, the kit includes protocol stack hardware that is preloaded into the MCUs, demonstration software (preloaded), and even the batteries. That is essentially everything an engineer needs to establish a simple point-to-point network for first-hand ZigBee experience. The kit includes an application note providing detailed "how to" and insight into the ZigBee software stack operation.

The ZigBee protocol addresses low data-rate control and monitoring applications with data rates of 250 kbps, 40 kbps, and 20 kbps for 2.4 GHz, 915 MHz, and 868 MHz channel frequencies. The specification targets low power consumption, long battery life applications that range from simple star networks to complex mesh or peer-to-peer networks. Three types of nodes are defined: Reduced Function Device (RFD), Full Function Device (FFD), and Coordinator.

Low-Power Approach

Targeted for control and monitoring applications, ZigBee is a moderate to low bandwidth wireless protocol with low power consumption and low overhead so it easily runs on an 8-bit microcontroller. Building automation, industrial automation, instrumentation, and home automation are among the early adapters for ZigBee technology. In building automation, lighting heating ventilating and air condition (HVAC) control, and security provide specific examples of ZigBee applications.

 
Easy wireless connection: The RF daughtercard on the PIC-DEM Z demo board uses Chipcon's CC2420 2.4 GHz transceiver with an integrated printed circuit board antenna.

The MCU selected for the demo board, the PIC18LF4620, uses Microchip's Nanowatt Technology for low power management, which complements ZigBee's low power design approach. With 64 kbytes self-programmable Flash memory and 4 kbytes RAM, this unit provides sufficient application space for user's code including diagnostics and experiments. The protocol stack for the reduced function, full function, and coordinator ZigBee nodes is about 12 kbytes. Since the software stack is written in C and available under a no cost license, it is easy to understand and mate to other transceivers.

Once the true application requirements are determined, something as small as a 28-pin packaged 8-bit MCU with 32 kbytes Flash memory could be used for production. In the PIC18 family, other products provide alternative choices for memory size, peripherals, I/O, and package types.
Microchip
http://rbi.ims.ca/4391-576

RF Kits Make Waves

Designing a wireless communication link into a product still requires solid engineering skills, but these days engineers don't have to become RF circuit design experts. In many cases, they can just drop a module into a circuit and get "on the air" quickly. To help designers, several companies offer development kits that ease the task of integrating radio-frequency (RF) communications in a product. Whether you must design a home security system or transfer data to a network, someone sells a kit that can give you a hand. RF devices in these kits range from simple radios to wireless modules that supply communication stacks, and general-purpose I/O lines, and that accept simple control commands.

To see what these design kits offer and how well they introduce developers to communication techniques and applications, Design News took a hands-on look. We approached five vendors and put their kits to the test to determine whether each served its purpose. Our lab work did not determine the suitability of a manufacturer's offering for specific types of applications. Based on our findings, engineers will benefit greatly when they buy one or two applicable kits and try them out.

The five kits we investigated include two that offer general-purpose communications, two that provide Wi-Fi (IEEE 802.11b) links, and one that contains ZigBee (IEEE 802.15.4) devices. Our descriptions below also cover one kit we saw demonstrated but did not test in a lab environment.

Other communication technologies, such as short-range Bluetooth (IEEE 802.15.1) and long-range Wi-Max (IEEE 802.16) offer alternative communication capabilities, but we didn't investigate them in this hands-on exercise. All the kits we tested operate within FCC-specified power limits and within the industrial, scientific, and medical (ISM) frequency ranges for unlicensed operations. Use of the kits requires that users know and follow FCC rules and regulations.

Digi International

http://rbi.ims.ca/4391-557 Digi Connect Integration Kit
(DC-WME-01T-KT; $249, Wi-Fi Kit)

The package sent from Digi included a development board, a Digi Connect Wi-ME module, an antenna, cables, a power cube, manuals, and a CD-ROM. The Connect Wi-ME module communicates with a host device over a serial port, and it provides five uncommitted I/O pins, a TCP/IP stack and an IEEE 802.11b (Wi-Fi) transceiver. The module mates with the development board and links to an access point (AP), typically a wireless router, on a network. So, if you need a Wi-Fi network connection, this kit can give you a head start. (Digi's kit does not include an access point.)The CD-ROM installed software and loaded an installation guide and documentation. After connecting the Wi-ME module to the board and applying power, I watched the board's LEDs, as instructed. A Status LED should have flashed as the module searched for and connected to the AP. Unfortunately, none of the board's LEDs flashed, and none was marked Status. It turned out the Wi-ME module contains two tiny LEDs, "Link Status/Integrity" and "Network Activity/Diagnostic," but neither the setup instructions nor the hardware reference manual identifies them for a Wi-ME module. This lack of detail in documentation frustrates me. Because I didn't view the development board from the antenna-connector side, I didn't see the LEDs. It turns out the Wi-ME module did detect the AP and the Network Reorienting the board made the Activity LED on the module visible, and it flashed as described. Next, I ran the Digi Device Discovery software from my PC networked with the access point. The software should detect the remote development board and report its characteristics. In this case, the software detected no active Wi-Fi networks in the vicinity and thus, no Wi-ME device. After several failed attempts, and with no help from the installation information, I eventually located "Release Notes" for the Discovery software on the Digi Web site. The notes warn against using a firewall between the Discovery software and the AP. Digi's set-up information, or a sticker on the CD-ROM should warn developers to check the company's Web site for up-to-date information, software changes, reported problems, and so on. To overcome problems with my firewall, I set up the Discovery software on an unprotected lab PC connected to my network, and that PC properly detected the Wi-ME module.The Discovery software's Web Management and Configuration interface let me check and change various parameters. Next, I decided to test remote control of the board and turn its LEDs on or off. Although documentation explains the development board's I/O ports and appropriate switch settings, nothing links that information to the configuration menus. I explored on my own and figured out how to control the I/O-port lines that drove the LEDs.The installed documents include code examples written in C/C++ for the Gnu Compiler Collection (GCC) that runs under Red Hat Linux 8.0, as described in the helpful ReadMe files. But developers who want to move beyond demonstrations and write code for the Digi modules should opt for the more capable Development Kit (DC-WME-01T-GN; $1495), which includes a complete suite of software-development tools. Digi's online support facilities include helpful technical documents and notes, and informative threaded discussions with users.My gripes with the Development kit center on several points: First, documentation should not skimp on the details. Things that seem obvious to manual authors often aren't obvious to users. Second, access to information on the accompanying CD-ROM should take place through a Web-browser interface. Third, more tutorial-level information that steps a potential developer through several simple applications will help attract users who need a bit of handholding.

DPAC Technologies

Garden Grove, CA
http://rbi.ims.ca/4391-558 Airborne 802.11b Wireless LAN Node Module Evaluation & Development Kit (WLNB-EK-DP001; $499, Wi-Fi Kit)

The DPAC kit aims to help developers make a Wi-Fi LAN connection and it furnishes a development board that includes a pre-mounted wireless LAN module (WLNB-AN-DP101). An antenna, serial cable, power cube, battery, and CD-ROM round out the kit's contents. Developers may not have an 802.11b Wi-Fi device available for experimenting, so DPAC also provides a Netgear Cable/DSL wireless router (MR814) as part of the kit.I have heard horror stories about installing wireless-network equipment, but the router installed easily and connected to my Comcast cable modem without any manual intervention. Next, I followed the brief quick-start guide and connected the development board to my lab PC. That setup went smoothly, too. The guide recommended using HyperTerm to communicate with the Wi-Fi module through a Telnet session between the lab (host) PC and the PC attached to the wireless router. That link also worked well.To understand the capabilities of the DPAC wireless LAN module, you must think of it as a communication processor, not just a 2-way radio. Each module includes a Web server, a TCP/IP stack, a command decoder, several I/O ports, and either a UART or an SPI interface. The availability of these serial interfaces eliminates the need for special driver software. Thus, you won't find C/C++ code examples in the documentation because you don't need them. Still, some "typical" settings and command set-up sequences might help developers.ASCII commands issued through a command-line interface such as HyperTerm control the module. The command, "wl-scan," for example, directs the module to scan for Wi-Fi access points and return information about any it discovers. Commands also control module I/O pins, and a command such as "adc-read g2," measures and returns a voltage from one of the Wi-Fi module's input pins. The development board routes I/O-port, communication, and control signals to connectors to ease engineering work. If you want to explore the capabilities of the development board, load the DPAC Airborne Evaluation Utility and print the user's manual for the evaluation kit. To learn more about the electrical characteristics of the Wi-Fi module and its commands, also print the Wireless LAN Node Module Data Book. The manuals--all on the CD-ROM--provide a wealth of complete and clear information about using the development board, the configuration software, and the modules. I recommend you print the manuals rather than try to browse through them using Adobe's reader.If you don't want to program communication settings through a command-line interface, use the module's built-in Web interface. I accessed the Web interface from my networked PC through the AP and the wireless link. After I made changes, I could save setup data in the module's internal flash memory or restore the factory default settings.Although the development board provided a Wi-Fi connection between my two computers and the cable modem, the kit will not connect to the Internet. The kit simply makes the Wi-Fi link. It's up to developers to determine what data gets transmitted and received and how an application that information.

Freescale Semiconductor

http://rbi.ims.ca/4391-559MC13193 Evaluation Kit
(13193EVK-A00; $1,980, ZigBee Kit)
The large Freescale ZigBee kit provides two MC13192-SARD accelerometer transceiver boards and three general-purpose MC13192-EVB transceiver boards. Each EVB board includes an RS-232 port and a USB port. Developers also receive a CD-ROM, batteries, power supplies, cables, an IEEE 802.15.4 ZigBee "sniffer" module and a background debug mode (BDM) programmer pod. A short-term version of Metrowerks CodeWarrior development studio software comes on a CD-ROM.The instructions explain the steps needed to set one SARD board to transmit x-, y-, and z-axis accelerometer data to a second SARD board that I connected to my lab PC. Graphic and numeric displays showed the results of moving the transmitter board, and flashing LEDs on the boards indicated they operated properly. This test confirmed I could run the embedded software and transmit a signal from one board to the other.To test ZigBee-communication range, Freescale provides another program that will run on either two SARD or two EVB boards. Although I followed the directions and the firmware seemed to load into the boards properly, I could not get the LEDs on each EVB board to display relative power levels. I also tried the software on two SARD boards with similar results. Talks with Freescale support people indicated a problem that required more investigations. I suggested the Freescale team download code using the bootloader and then examine or extract the code using the separate background-debug module. That way they would have independent download and upload paths to check for code errors. Freescale's engineers recommended I shipped my boards back to them for a closer look, so off went the boards. I received a new set of boards in return.It turned out the downloaded code was fine. The Freescale support staff determined I needed to enable a firmware-upload setting that would erase each board's Media Access Control (MAC) address. The manual does not include that step. After reloading the range-test software, the boards operated well and I measured a good signal out to several hundred feet over a clear line-of-sight path. The instructions leave a lot to be desired, though. In addition to the missing information about the software setting, file names did not match those on my disk and instructions lacked details.While waiting for a reply from Freescale's tech-support people, I skipped ahead to the Protocol Test Client (PTC) application (Section 5.8). Running this test requires loading new firmware into the transceivers, but the instructions do not explain which of the Embedded Bootloader's three listed PCT files get sent to a transceiver. Instead of taking a cut-and-try method, I skipped ahead to the Command Console software that lets developers send 801.15.4 commands directly to the evaluation boards. It seemed like a big leap from running demonstration programs to sending ZigBee commands to transceivers and I wonder how many people will "jump" across that chasm.One of the people I spoke with at Freescale said most developers skip the demonstrations and start to program with the "Wireless Z-Stack." A company called Figure 8 Wireless (www.figure8wireless) offers the Z-Stack software, essentially an application-programming interface (API) that simplifies ZigBee communications programming. Freescale also supplies a 90-day evaluation version of the Z-Stack that developers can download. For more information, go to www.freescale.com/zigbee. Click on Software Tools and look for the Protocol Stack listings. If you want to proceed without the Z-Stack, the CD-ROM that comes with the kit contains C/C++ source code for all the examples.The technical-documentation CD provides information about the SARD modules, but if you want to dig into the Freescale 802.15.4 MAC/PHY software--the software that links the transceivers to an application--you must go to the Freescale Web site, register, and download documents and code. Clicking on the SMAC Software and Applications link under the MC1319x Family (MC13191/92) Software and Development Tools heading creates a link that lets you download code files for seven example programs, all written in C. These samples start with a basic initialization of the MAC and culminate in a complete application that will receive data in a network. The Freescale documentation suggests downloading several manuals, which I did, just to see what they contain. The "802.15.4 MAC/PHY Software User's Guide" and the "802.15.4 MAC/PHY Software Reference Manual" are must-have documents if you want to learn more about how to use the transceivers in a simple application.  The C-code can get complicated, so don't expect to master programming a ZigBee application in a few lab sessions. I applaud Freescale for making its demo source code available.The MC13193 kit comes with a receiver module and ZigBee "sniffer" software that monitors transmissions and decode them in several ways. When I encountered problems with the range test mentioned earlier, I used the sniffer to detect and monitor any ZigBee transmissions. The sniffer software, from Frontline Test Systems, proved easy to set up and use, although it took some experimenting to figure out how to view ZigBee packets. Unfortunately, Freescale did not supply information about the operating channel its modules use, so it took several trial runs to determine they use the 0x0b channel at 2405 MHz. After setting the operating channel, the sniffer detected the operating transmitter and displayed its output in several formats. Freescale's documentation does not explain the LED indicator on the sniffer module: red for "hardware can't send data" and green for "reading a packet." Frontline's technical-support person responded quickly to a telephone request for this and other information.The Freescale kit provides many opportunities to experiment, but the lack of tutorial information beyond the demonstrations will make it a difficult sell to developers new to ZigBee applications. Why not run developers through an example that illustrates how to modify existing code to control the LEDs on the development boards via a wireless link, for example? Even if you choose to experiment with the LEDs on your own, you won't find the schematic diagram for either the SARD or EVB circuits on the CD-ROM. I did find the diagram on the Freescale Web site, along with the PCB reference design, but I had to register and agree to a "license" before I could download it. Good luck reading the schematic's tiny print.The 13193EVK User's Guide refers to an evaluation-board reference manual, but a search of Freescale's Web site for the manual's part number--13192EVBRM/D--turned up nothing. Poking around the ZigBee portion of the site uncovered the manual as 13192EVBRM--no /D on the end. This sort of mismatched information turned up often in the Freescale manual, which gets low marks for usability. The Freescale kit suffers from documentation errors, lack of completeness, and little handholding for newcomers to ZigBee technology. If you can get by these annoyances, you'll find the Freescale kit has a lot to offer.

Chipcon

http://rbi.ims.ca/4391-562ZigBee Development Kit (CC2420 ZigBee DK; $5,000)
Chipcon offers several demonstration kits that incorporate the company's line of ZigBee communication chips. Instead of sending a kit, though, my Chipcon contact suggested I watch a demonstration of the CC2420 ZigBee Development Kit set up for a seminar. (Chipcon also sells less-expensive starter and demonstration kits.) Although I found the walk-through informative, nothing substitutes for getting your hands on real hardware.The kit comes with lots of hardware as well as development tools for the onboard AVR microcontroller. I saw several tests run and I watched a demonstration of the Chipcon ZigBee sniffer module and software. The sniffer produced a helpful display of ZigBee traffic and it breaks a transmission into easy-to-read MAC header, beacon, data, command, and other segments. The development boards worked as expected, but I missed having an opportunity to try them for myself. Chipcon recently acquired Figure 8 Wireless, the supplier of the Z-Stack software for ZigBee devices, so developers can take advantage of a Z-Stack API that works with the Chipcon boards. Figure 8 Wireless also offers a four-day course ($4995) on developing ZigBee applications.Please note: Chipcon Kit was not actually tested

Linx Technologies

http://rbi.ims.ca/4391-560 Master Evaluation/Starter Kit
(ES Master; $179, General-Purpose Kit)

RF communication cannot get much simpler or easier than the way Linx Technologies presents it in this kit, which demonstrates simplex (one-way) communication. This type of communication works well for alarms, remote controls, status monitors, data links, and similar short-range applications. The kit includes a receiver board, a transmitter board, antennas, batteries, a CD-ROM, and lots of documentation. The transmitter board provides two pushbuttons that control a relay and a buzzer on the receiver board. During testing, I measured a range of about 50 ft for the 1-mW transmitter after its signal passed through several walls. While testing outdoors, I placed the transmitter on a ground plane and received the signal at 300 ft over a clear line-of-sight path.

The single-channel transmitter operates at 916.48 MHz and its input accepts either an analog signal that produces an FM output, or a digital signal that produces a frequency-shift-keying (FSK) output. Linx Technologies specifies a maximum data rate of 56,000 bits/sec and recommends a format for digital data that will ensure the receiver locks onto a transmission. The transmitter and receiver chips send and receive what you give them. They do not apply a protocol or data encoding, nor do they perform any timing or error correction, they simply pass a signal.

Each board provides an RS-232 serial port for simplex data communication. The Linx Master Development 2.0 software includes a serial-communication program that lets one computer transmit data to another. I loaded the development software into two PCs, changed the jumpers as detailed in the user's guide, and transmitted typed character strings from one computer to the other. The receiver seemed to miss about every fifth or sixth string, but the errors may have more to do with timing of the Windows-XP operating system than with the radios. A bit-error-rate test over a 15-ft range, detected no errors during a 15-min experiment that involved transmitting about 1M bytes. In addition, the program transferred a small image flawlessly.Keep in mind that simplex transfers do not let a receiver request a retransmission of data. Developers can overcome errors by including error-detection and error-correction protocols or through redundant transmissions. In a meter-reading application, for example, the meter could transmit data 50 times in rapid succession to ensure the receiver picks up good data. And, transmissions could include error-detection bits.The receiver does not include a squelch circuit, so the receiver produces noise when powered and not receiving a signal. The development board provides an external squelch circuit, but I did not experiment with it. If you want to add a microcontroller or other circuit, each board provides signals at wire-wrap pins and an area for breadboarding.The kit comes with an extra transmitter and receiver chip and printed specifications and design information for each. Developers can use the kit's boards as reference designs for their own PCB layouts. Linx also provides a helpful 72-page booklet that describes FCC rules and regulations and the FCC approval process for unlicensed RF devices. I liked the completeness of this kit and think the Linx devices will serve well in many short-range applications.

MaxStream

http://rbi.ims.ca/4391-5619XTend-DEV 900-MHz Development Kit
(XT09-DK; $499, General-Purpose Kit)
When an application calls for basic 2-way communications that don't require a standard protocol such as ZigBee or Bluetooth, the MaxStream kit deserves your attention. The kit comes with a pair of XT09 long-range RF modules each mated to an XTIB-R interface board that connect to a device or computer through an RS-232/422/485 port. (Each module pair provides an unpackaged version of the company's standard XTend RF-modem.) Provided accessories include serial cables, serial-port adapters, power cubes, antennas, and a CD-ROM. I installed the X-CTU software from the CD-ROM and started it from my Windows lab computer.Hardware setup involved only connecting power and an antenna to each transceiver and checking DIP-switch settings. Software setup requires starting the X-CTU program and checking or setting serial-port information. To begin testing, I ran a range test that employed one transceiver at my lab PC and a remote transceiver connected to a serial-port loop-back connector (supplied). The PC-based unit transmitted strings of ASCII characters that the remote unit simply retransmitted. The PC-based software compared the sent and received data to detect and count any errors. Accumulating statistics indicate good and bad communications. (Packets of data include a header, application data, error-detection codes, and other information, not just the ASCII characters.)The range test ran error free in my work area, and walking with the battery-powered loop-back transceiver in hand produced a solid signal out to at least a 1000-ft (300m) over an RF path obstructed with trees, snow, and houses. Three green LEDs on the transceiver showed relative RF signal strength during the tests with one mW of power. Higher-power settings would have increased the range, probably to several miles. Unfortunately, I lacked a sufficiently large and unobstructed site for testing. (The transceivers will operate in a network or point-to-point configuration. I used the latter mode.)The X-CTU software provides a Terminal program that independently transmits and receives. To test this mode, I set up the X-CTU software on a second PC and replaced the loop-back connector on the remote module with a connection to that PC's serial port. Error-free communications took place from PC to PC. Transceiver control occurs quickly and easily through standard AT-modem-control commands or serial binary commands that establish encryption, power levels, module addresses, and so on. In operation, an XT09 transceiver module requires only a serial interface, found on most microcontrollers or microprocessors. Thus, the modules should easily drop into most designs that need RF communications. If you can operate without an industry-standard protocol, this type of device deserves a look. I wish I had more time to experiment with the many communication capabilities this kit offers.To simplify custom setups, the X-CTU software includes a Modem Configuration menu. Simply select the module in use and choose the parameters you want to modify. But before you change any settings, print the XTend-PKG-R RS-232/485 RF Modem manual that details the operation of the XT09 module, as it exists on the interface board. Each command reference includes a clear explanation, parameter ranges, a sample setting, a default setting and information about any acknowledgement bytes returned. If you scramble settings, an AT command string will reset and reprogram the default characteristics.Because the transceiver responds to 59 commands, it would help to have the manuals define and explain several fundamental command strings  that let a pair of transceivers communicate under several conditions. Not everyone will want to use the factory settings, and learning how to combine commands in useful ways will help developers get started. Of course, they can always begin with the default settings and modify them one at a time, but that may waste time. (If you change one transceiver's settings, you may need to program the same settings in the other transceivers in your communication system.) Wi-Fi Devices

Wi-Fi devices can operate within a standard network and they provide a convenient way to let a product connect to a nearby local area network. The network could offer access to Internet services or corporate resources, or it might simply provide communication with a shared resource, such as printer, home-entertainment system, and so on.

Product Best Features Ease of Use Applicability Limitations Comments
Digi International, DC-WME-01T-KT, $249, Mode: Wi-Fi, http://rbi.ims.ca/4391-557 · Powerful and capable modules for embedded application when you don't want to become an RF expert. · Serial port on modules eases programming and setup. Will work well in Wi-Fi applications Incomplete documentation and lack of tutorial may slow development. · Slow setup due to poor documentation and lack of configuration update information.
·Programmers should have no difficulty with this type of module. · If you're interested in Digi modules, buy the larger development kit.
DPAC Technologies, WLNB-EK-DP001, $499, Mode: Wi-Fi, http://rbi.ims.ca/4391-558 · Easy setup and operation. · Easy setup and operation, clear explanations of commands and operations. · Highly recommended as a way to provide Wi-Fi connectivity to a network. Nothing worth mentioning. · Nice development board that allows for experimentation and prototyping.
· UART and SPI interface eases development. · Built-in Web interface simplifies setup and control. · I/O control requires no programming. · Clear and helpful manuals and documentation.
Freescale Semiconductor, 13193EVK-A00, $1,980, Mode: ZigBee, http://rbi.ims.ca/4391-559 · Kit provides demo and development boards. Incomplete or wrong instructions caused initial setup problems. The instruction manual (Rev. 0.0) needs work. Developers can use the EVK boards as a reference design and for prototyping. · The lack of more tutorial information may put off newcomers to ZigBee technology. · To keep costs low, designers work at the chip level and design RF PCBs and antennas.
· ZigBee sniffer module eases testing and troubleshooting. · Requires C/C++ programming to get the most from the EVK boards. · Freescale technology quickly overcame setup difficulties.
· Z-Stack should ease C/C++ programming.
Linx Technologies, ES Master, $179, Mode: Unformatted FM, http://rbi.ims.ca/4391-560 · A solid performer for short-range simplex communications. Easy to set up and use. Good for one-way communications used for meter reading, data acquisition, short-range remote control and similar applications. · Developers must control protocols, data formats, error detection, encryption, and so on. · The company offers other types of radio devices, antennas, and accessories.
· Serial port simplifies testing. · Designs involve basic FM radio chips, which will need external circuitry. · Helpful FCC regulation booklet.
MaxStream, XT-09-DK, $499, Mode: Proprietary, http://rbi.ims.ca/4391-561 · Easy to use, program, and drop into an application for point-to-point or networked communications. · Clear manuals make setup easy. · Good for high-speed, two-way communications that don't require industry standard compatibility. Proprietary protocol, but most users won't care. · Modules provide 256-bit AES security.
· Use this approach when you don't need a standard protocol. · Easy to program. · Modules use ASCII commands for programming. · Programming examples would be a bonus.
· Would like to experiment more with this kit.

The Web version of this article includes more observations and comments about the Digi International, Freescale Semiconductor, and MaxStream kits. Also, we welcome your comments about adding wireless capabilities to a product. Have you used a development kit? What was your experience? Share your thoughts with Jon Titus at [email protected].

The Food Giant Wish List

When it comes to performance, what is Kraft looking for in packaging equipment?

Hand: From a control standpoint, we view speed and reliability as important characteristics—so much so that we ask vendors to guarantee speed and uptime on machines. In addition, we want more integration of motion control in the packaging environment.

Gowens: We also look for equipment that is compatible with a wide range of packaging materials that we choose, allowing us to easily flex with ever changing market needs, while simultaneously minimizing recapitalization and enabling quick turnaround of new packaging designs. Another key requirement is the ability to run various packaging formats with ease of changeover.

How have these demands changed in recent years?

Gowens: The changes have pressured packaging equipment suppliers to deliver more. Take the bottling types for our Enhancers line of salad dressings. In the past, we might have run separate equipment lines for different bottle shapes. Today, we want machines that handle various bottle types on the same packaging line—with higher speeds and tighter weight control for contents.

What trends do you see in networks for connecting your machines?

Hand: Ethernet continues to grow as a bus system. Long term, we expect Ethernet to meet communications and performance needs at a lower cost while also integrating motion control.

What progress have equipment providers made in designing "plug and pack" capabilities into machines, as encouraged by the OMAC (Open, Modular, Architectural Controls) Users Group?

Hand: The change is just starting in terms of the number of equipment vendors who are meeting this OMAC challenge. The plug-and-pack concept is a good one, but the industry is still trying to define what interoperability and nonproprietary mean. We still see too much complexity when introducing equipment from a variety of vendors. Kraft uses its own control standards with strategic packaging equipment suppliers to achieve the plug-and pack capability we need.

Which equipment innovations do you see as most significant?

Hand: The most impressive developments are the flexibility of equipment design and the integration of motion control. Another key development is the combination of machine vision with robotic systems. This has allowed us to further automate the packaging process. While Kraft has been implementing machine vision for a number of years, we now see advances in cameras and lighting systems, such as LED panels, that yield better results and solve earlier concerns about reliability and maintenance. Vision tools also are much easier to use.

To what extent will Kraft be using RFID tags versus traditional bar codes?

Hand: In 2005, Kraft is supporting a number of electronic package code (EPC) pilots, but we are focusing primarily on supply chain efficiencies. We see more EPCs being used on cases and pallets—but not on individual consumer packages. However, there are many issues that EPC/ RFID technology needs to solve before it can be implemented cost-effectively across the supply chain. These issues relate to technology reliability, intellectual property, standards, and consumer privacy. Manufacturers, retailers, and suppliers need to work together.

Looking ahead, what are the biggest challenges facing the packaging industry?

Gowens: We always focus on growth opportunities that can be driven by packaging innovation. The problem is that all too often it takes too much time to develop the packaging technology to support these great ideas. So the biggest challenge is developing solutions, such as custom equipment, that will help us commercialize our ideas more quickly.

   Evan HandLeader, Electrical Center of Functional Leadership,Kraft Foods
   
Patrick GowensSenior Program Leader,Global Packaging Organization,Kraft Foods

Lords of the Rings

Introduction

Berran Industrial Group designed a packaging machine that attaches small tags to rings and then seals each ring in a small plastic bag. The jewelry company wanted an automated way to verify that each bag contained a ring, but for several reasons the sensors we use for other applications could not reliably perform that detection. Our solution, after much trial and error, was to use an OMNI-BEAM accoupled sensor with fiber-optic cables.

The Problem

The patented packaging machine that Berran built for the jewelry manufacturer attaches small price tags to rings and then seals each ring in a small, clear, plastic bag. The process, which takes just a few seconds, has several steps. First, the feeder moves the leading end of a continuous, perforated roll of poly bags into position. Then an air jet emits a puff of air that opens the 3-inch × 2-inch pocket in the roll, and a ring drops down the shoot and into the bag. When the sensor detects the ring as it falls into the bag, the sealer bar moves into position and quickly heat-seals the bag, which is then cut from the roll. Puff, drop, seal, cut—at a rate of about 40 cycles a minute.

The value of the rings necessitates tracking them throughout the process, so the jewelry manufacturer specified that a sensor inspect each bag before it is sealed to make sure it contains a ring. This requirement proved problematic for several reasons:

  • Because the sealer bar closes the bag right after the ring drops into it, the presence of the ring has to be detected during the fraction of a second that is actually falling.

  • Wrinkles in the surface of the bag reflect light, which could trick the sensor into thinking that the ring has dropped before it actually drops, triggering the sealing bar too early. As a result, the bar could crush an expensive ring or, the ring could fall to the floor and be damaged or lost.

  • The sensor has to be versatile enough to accommodate the differences in sizes of rings.

  • The path the ring follows while falling into the bag is inconsistent; it can fall anywhere within the 2-inch width of the bag.

  • The sensor has to fit into a confined area.

Adding to the challenge, the customer required a detection rate of 100 percent.

We tried photoelectric sensors, several fiber-optic sensors, and a capacitive ring sensor. It was a massive problem. Every sensor supplier with whom we work looked at the problem and said they had the solution. Some of the setups we tried worked some of the time—if the ring dropped just the right way—but none worked with the reliability that the customer needed.

We'd evaluated and rejected about a dozen sensors when I called in Ken Prahlow, one of the owners of MC2 Inc., in Cleveland, OH, a representative for Minneapolis-based Banner Engineering.

The Solution

Ken borrowed a solution widely used in the automotive and metal stamping industries, recommending that we try an OMNI-BEAM™ sensor in opposed mode, coupled with an ac amplifier. In addition, he suggested using a pair of fiber-optic cables with 40-mm slotted ends as the "eyes" of the sensor—one cable connects to the emitter in the OMNI-BEAM, the other to the receiver—and placing an end on either side of the roll of plastic bags just below the shoot.

Here's why Ken suggested this setup:

  • Ac-coupled amplifiers detect only quick changes in the light level. They are too sensitive for many applications because they might respond to unwanted conditions, such as vibration. But for this application, it provides the sensitivity needed to detect a ring—no mater how delicate—at the instant it drops into the bag.

  • The fiber optic array senses the entire width of the bag, not just a point, so the path of the dropping ring doesn't matter.

  • Because the sensor uses an infrared LED, it only detects infrared light, which is outside the visible spectrum. Ambient light on the production floor is irrelevant.

  • With cables on either side of the bag, the sensor operates in opposed mode— it looks through the bag—so the wrinkles no longer cause a false trigger. As the ring drops into the bag, the receiver on one side senses the quick decrease in the amount of light it's picking up from the emitter on the other side.

  • The fiber-optic cables are small enough to fit into the machine.

The sensor works, 100 percent of the time. The beauty of the solution is not that it used a dazzling new technology; in fact, the OMNI-BEAM has been around for a long time. The beauty is that the solution applies a proven technology to a dilemma that the industry's usual solutions couldn't reliably handle.


Web Resources
» Berran Industrial Group Inc.
http://rbi.ims.ca/4409-531
» Banner Engineering
http://rbi.ims.ca/4409-532
» MC²
http://rbi.ims.ca/4409-533

Electronics

ABSOLUTE ENCODER

For miniature applications

Designed for applications where limited space is a factor, the MAS10-256-G is reportedly one of the smallest absolute rotary encoders in the industry. It measures 13 mm in diameter and 17.5 mm high. It is designed for a variety of applications, including medical devices, instrumentation, and robotics. It delivers 8 bits of absolute position information with a gray code, parallel output. It is capable of operating within a 0-60C range, and it can measure the rotary process as fast as 6,000 rpm.
CUI Inc.

http://rbi.ims.ca/4391-577

CAPTIVE LINEAR ACTUATOR

Durable design

The company's size 8 captive linear actuator is designed with an HIS patented integral anti-rotation mechanism. It is suitable for applications in which external anti-rotation methods would be difficult or impossible to employ. It features engineering thermoplastics in the rotor drive nut and a stainless steel Acme lead screw. It is available in resolutions ranging from 0.0015 to 0.04 mm per step, and it delivers thrusts of up to 4.5 kg.
Haydon Switch & Instrument Inc.
http://rbi.ims.ca/4391-578

CONVERTERS

Rated up to 50A

The PAF600F280 series is designed as a high-efficiency family of 600W full-brick dc-dc converters with a nominal input of 300V dc. They are suitable for systems using distributed high-voltage dc power architecture and for users designing custom off-line power supplies. It is rated up to 50A and is available with 12, 24, 28, and 48V outputs. Features include over-current and over-voltage protection, remote sensing, output adjustment trim, remote on/off, current-sharing capability, a converter-good signal, as well as auxiliary voltage for housekeeping functions.
Lambda
http://rbi.ims.ca/4391-579

OPERATOR INTERFACE TERMINALS

Electronics upgraded

The electronics of the QTERM-G70 and QTERM-G75 rugged graphics operator interface terminals has been upgraded. New hardware features a 400 MHz Intel® XScale core platform with 8 Mbytes of Flash memory and 32 Mbytes RAM. They are designed for rugged industrial and vehicle environments, and they feature Ethernet-enabled color touch screens. The products use the company's object-based programming environment named Qlarity.
QSI Corp.
http://rbi.ims.ca/4391-580

SENSOR

Detects fluorescent agents

The CZ-H52 UV sensor detects the presence of fluorescent agents used in a wide variety of products and packaging materials. It emits a UV light beam from the transmitter in the sensor head; the receiver picks up the visible light reflected by fluorescent materials. The product detects materials that are not only invisible to the naked eye but also cannot be detected by ordinary photoelectric sensors. Background colors and patterns do not affect sensor performance.
Keyence Corp. of America
http://rbi.ims.ca/4391-581

SOFTWARE SUITE

Completes projects faster, cheaper

The FactoryFloor 4.1 industrial automation software suite is designed for use with the company's line of process automation controllers, typically combined with the company's SNAP Ethernet I/O and SNAP Serial I/O products. Using the software, users can develop powerful and diverse control programs; design human machine interfaces; expand control systems' connectivity to enterprise databases; and complete control and data acquisition projects faster, at lower costs, and more easily. It includes new security and auditing features for controlling and logging operator HMI use.
Opto 22
http://rbi.ims.ca/4391-582

MODULAR I/O PRODUCTS

256 digital inputs

Compatible with the company's SynqNet network, the family of modular SynqNet I/O products is comprised of a SynqNet Interface Device (SQID) and flexible analog and digital add-on boards that provide machine builders with a modular and cost-effective high-count I/O solution. It can be easily integrated to work with existing machine I/O, and is also offered as part of a developer kit solution for custom OEM solutions. The product family provides up to 256 digital inputs and outputs and 16 analog inputs and outputs per SQID. Motion Engineering Inc.
http://rbi.ims.ca/4391-583

ALTERNATOR-REGULATOR

Data received in single pass

The company has introduced a local interconnect network (LIN)-controlled alternator-regulator for next-generation vehicles. It is designed to optimize performance in intelligent automotive charging systems for increased efficiency and improved fuel economy. It offers integrated programmable load response control features, programmable field excitation of current or temperature, and regulator feedback of fault status. It can be addressed for compatibility with up to 15 other modules on the bus, and all data can be transmitted or received in a single pass.
International Rectifier
http://rbi.ims.ca/4391-584

VISION SENSOR

Delivers high-speed error-proofing as well as inspections

Able to accurately sense and evaluate more than 10,000 objects per minute, the P4 EDGE is fit for validating the height and width of parts, finding the location of labels, or detecting the edge of materials such as plastic or paper on a Web operation. Other features also make it easy to deploy and be operational quickly. For applications where product lines are constantly being changed, a remote TEACH feature allows the sensor to learn new elements it will need to inspect without connecting to a PC or shutting down the line. It can interface to machines and factory networks via its built-in 10/100 Ethernet connection, RS-232, or discrete input/outputs. Included mounting brackets facilitate easy location of the P4 EDGE sensors on machines or conveyors. The units feature three bicolor LED indicators to clearly show unit status during setup and operation.
Banner Engineering
http://rbi.ims.ca/4391-585

PRESSURE SENSOR MODULE

Low power, low voltage

Intended for consumer, medical, and general applications for barometric pressure/altitude, the MS5534B is an SMD-hybrid device including a piezo-resistive pressure sensor and an ADC-interface IC. It provides a 16-bit data word from a pressure- and temperature-dependent voltage. Additionally the module contains six readable coefficients for a highly accurate software calibration of the sensor. The MS5534B comes with automatic power down (on/off) switching, and a three-wire interface for all communications with a microcontroller. Sensor packaging options are plastic or metal cap. Compared to the previous generation, the temperature range has been improved (-40 to +125C) as well as the pressure range (measurement down to vacuum). Other improvements have been made with ESD sensitivity, current consumption, and converter accuracy. Servoflo Corp.
http://rbi.ims.ca/4391-586

ANGULAR POSITION SENSOR

Intrinsically linear

The new "ILAPS" noncontact angular position sensor provides intrinsically linear output over 120-degree maximum travel without the need for electrical compensation. According to the company, it is fit for pedal, throttle, and valve position sensing. Complete technical information and a free product sample are available upon request.
Cherry Electrical Products
http://rbi.ims.ca/4391-587

TWO-PHASE HYBRID STEPPER

Miniature in size

The 208 is reportedly the smallest two-phase hybrid stepper to date. This 1.8-degree bipolar NEMA 8 miniature step motor is intended for applications where space is limited. The motor measures 0.79-inch square and is available in two stack sizes: 1.30 and 1.69 inches in length. Although it weighs a mere 0.13 lbs, it is still capable of up to 4.2 oz-inches of holding torque depending on stack size. The 208 is also available with a standard rear shaft extension. Suitable applications are medical, communications, semiconductor, and robotics. Lin Engineering
http://rbi.ims.ca/4391-588

ANALOG SENSORS

With nontraditional housings

Nontraditional housing styles are exemplified on the Bi20R-Q14-LU ring style and the Wi70-M18-LIU5 probe style sensors. These analog sensors are specified with a repeatability of less than 0.5 percent and linearity of 3 percent. The Bi20R-Q14-LU is a three-wire, 15-30V dc sensor with a 0-10V output in a ring-style housing with a 20-mm diameter hole. This sensor is fit for the identification and sorting of small parts (such as screws) as the sensor generates a different output signal for each size part. Position control applications can be resolved with the Bi20R-Q14-LU by means of a cone-shaped target as well as the detection or measurement of tools (such as drill bits). The Wi70-M18-LIU5 is a four-wire, 15-30V dc analog sensor with either a 0-10V or 4-20 mA output. Housed in a standard 18-mm barrel, the 75-mm probe has a linear operating distance of 70 mm. This probe style sensor can detect all metals and can be used in a variety of areas, such as the positioning of metal parts as they move over the length of the probe.
TURCK

http://rbi.ims.ca/4391-589

HALL-EFFECT SNAP SWITCH

Comes with sensing fuctions

The D4 Series snap-action switch with Hall-effect technology is tested to 10 million operations and reportedly goes where no switch has gone before. Technical information and a free product sample are available upon request.
Cherry Electrical Products
http://rbi.ims.ca/4391-590

MULTI-SEGMENT TYPE 4 SAFETY LIGHT CURTAIN

Allows for quick setup and changeover for different job requirements

The MiniSafe Flexible MSF4700 family of safety light curtains are engineered to withstand high shock and vibration environments typical of punch presses and other heavy industrial machinery. Their multi-segmented design allows them to protect up to four different openings by connecting up to four 35 × 50 mm housings in sequence. Protected heights from 150 to 1,800 mm, and resolutions of 14 mm, 20 mm, and 30 mm are also available, with any combination thereof being possible. This ability to customize height and resolution for each light curtain segment allows for a true custom fit to the specific machine. In addition, remote fixed-blanking allows for quick setup and changeover for different jobs. The controller is available in a 35- mm DIN IP20 enclosure with 24V dc solid-state safety outputs. It is also available in a 14 gauge steel IP65 lockable enclosure with a choice of solid state or dry contact outputs (mechanical relays).
Scientific Technologies Inc.

http://rbi.ims.ca/4391-591

Is Turnkey HMI Right for You?

"The cheese stands alone, the cheese stands alone." The phrase may have made sense in a childhood nursery rhyme, but when it comes to human-machine interfaces and visualization systems, the concept just doesn't apply. Once simple, self-contained entities of switches and push buttons, HMIs no longer stand alone in the manufacturing environment. They are part of larger systems and must therefore be integrated with business and information systems, as well as with the devices they monitor and control.

HMIs have grown into this larger role because they now do much more than present a visual rendition of an operation or provide a mechanism for process monitoring and control. Modern HMIs are complex components in complete solutions. They are used extensively for analysis and perform elaborate system activities. These characteristics are prompting users to give increasing consideration to a systems or turnkey approach when specifying and installing HMIs.

Why Turnkey?

A turnkey solution generally means using a single-source vendor or working with an integrator—or both. Such a systems approach has advantages and disadvantages. "One-stop shopping may not always get you the latest technology," says Rami Al-Ashqar, product manager, Bosch Rexroth Electric Drives and Controls, adding that a specific vendor may have the latest technology in one area but not in another.

Renée Brandt, Wonderware product marketing manager for visualization products, agrees. "Hardware vendors often want you to use their software, but it might not be the best software available for the job. It might not be the easiest to use or upgrade or integrate with other systems. When looking at a turnkey system, the end user needs to be sure that whoever is chosen for the job will select the best possible product for all the components."

In spite of the caveats, the advantages still probably outweigh the disadvantages. "By selling our own complete system—HMI, PLC, motors, drives—we are in a better position to know if there's a problem, where it is, and how to solve it," says Al-Ashqar. In addition, he adds, having a single source for service and repair means the end user doesn't have to call several people to get one thing done.

Mark Hobbs, product marketing manager, RS View, Rockwell Automation, summarizes the turnkey approach with an historical perspective: "Ten or 15 years ago, it was not uncommon to run into a customer who wrote his own custom HMI code. There weren't a lot of options, and if he couldn't find what he wanted, he created it. This is one level of turnkey system. Now times have changed. Most companies don't have the staff to do that. And they need systems that are global, not local. So they look for off-the-shelf solutions they can configure to their needs. This is another level. If that's still more than the company wants or is able to do, a system integrator (SI) or the services group of a major vendor can create the entire HMI project."

It is an interesting time to talk about whole systems as a solution, says Roy Kok, director of HMI/SCADA product marketing, GE Fanuc Automation. "Systems, not products, are what's important today. GE Fanuc's Proficy is one example of an integrated technology solution. It is a modular product. If you create something once, it is reusable elsewhere in the system. That kind of integration is hard to achieve if you buy an HMI from one vendor, a PLC from another, and a data historian from another. We recognize this challenge and Proficy is designed with an open and layered concept to facilitate layering on and integration with third-party offerings."

 
Turnkey HMI system controls and monitors precision vial-filling operation on a liquid filler machine for pharmaceutical packaging. An HMI system typically includes computer hardware, display mechanisms, and input devices, along with connectivity elements such as PLCs and drives. All components must work with each other and interact with plant business and information systems to achieve an integrated approach.

Importance of Planning

A turnkey approach requires a lot of upfront planning. Stresses Wonderware's Brandt, "When you're choosing someone to do a turnkey system, it's beneficial to find a supplier who has experience in the plant's own area and a good track record of successful installations. Discuss what you hope to achieve with the new system. Are you looking to upgrade old equipment? Do you need better quality? Do you have to comply with government regulations? Whoever you work with needs to know what to do and what's he's in charge of."

Adds Bosch Rexroth's Al-Ashqar, "If you're going to take this kind of approach, you need to know your purpose. You need to have a design and a plan. Who is going to use the system? What will the operators be required to do? In what kind of environment will the system operate? What kind of display is needed? And these are only some of the questions that need to be answered before you start."

The end user understands his application best, says Graham Harris, president of Beckhoff Automation. "A solutions provider or system integrator can provide expertise, but those who use the system need to embrace it as their own. We can give our experience, but only the customer can look at it all. He has to think it through from the physical configuration to the control loops to the actual displays, and make sure he has optimized every element. He needs to look at both hardware and software sides."

Integration, Interoperability

 
In this example of a turnkey HMI system from Opto22, an I/O module (top), controller, and HMI display/software work together to monitor and control a pumping system at a water bottling plant.

Turnkey systems must interface at the device level and with business and information systems. In fact, connectivity and open architecture are probably among the most significant areas of activity affecting an HMI system today. Applications of Ethernet, Web browsers for remote system monitoring and control, OPC servers for communication between disparate systems, and wireless capabilities, present expanded opportunities, but also significant challenges.

"Each individual component can be wonderful, but it's the system that solves the problem," says Russ Agrusa, president of Iconics. "The biggest problem with PC-based HMI systems is communications. An open-system solution needs to have the ability to work with data historians, pocket PCs, mobile phones, etc. It needs to integrate with the enterprise, the IT infrastructure, and an ERP (enterprise resource planning) system. If the products you're using to build your system are Microsoft-certified and OPC Foundation-compliant, you've got a pretty good shot at having your system work well together."

Achieving that seamless integration is the primary reason for using a single-source system, according to James Davis, systems engineer at Opto 22. "A thorough understanding of the project by the supplier and of open system concepts should be two primary considerations of anyone embarking on a turnkey system," Davis says. "Systems need to integrate with databases using open protocols. Discuss these aspects, discuss the entire project before it starts. Make sure whoever you work with knows what is important to you."

Turnkey systems have to work with existing systems, even if new hardware is being installed. "Most times, plants aren't replacing all of their business systems or all their controls," points out Wonderware's Brandt. "They may be upgrading only a part of their operation. A key factor is the ability to integrate with the products you don't want to change."

Visualization of the Future

 
Key to turnkey HMI systems is the variety of operator interface panels that provide flexibility for industrial applications, such as these from Beckhoff Automation. TFT displays come in sizes and resolutions to meet most needs and can incorporate touch screens, touch pads, keyboard, and more.

Working with a turnkey supplier or integrator lets an end user focus on business issues, observes Brandt, not on becoming an HMI or software expert. "The company can concentrate on improving productivity and quality, instead of worrying about new technologies," she says.

Observes Maria Piazza, commercial director, automation solutions, GE Fanuc Automation, "Applications are becoming more complex, and customers are making performance/price trade-offs. A flexible system solution lets them pick and choose the functionality they want and need, to build into the system a migration path that makes upgrades easy and economical."

HMI today is an integral system within a system amidst rapidly changing technology. Advances let today's HMIs provide data, graphics, and animation capabilities that, says Rockwell's Hobbs, "are truly amazing. And it will only get easier and better." An HMI solution affects the whole manufacturing process and must be considered as such. With proper design, planning, and execution, the turnkey approach can reap many benefits.

Reach Jeanine Katzel at [email protected].