OEM engineers have a wide range of development options, from designing at the component level to optimize cost to developing at the subsystem level to dramatically cut development time. Often, making a good decision on these trade-offs is the difference between profit and loss. For lower-volume OEM designs in the hundreds to thousands of units per year, “application-specific” subsystems are often used to prototype, get to market quickly, and test market acceptance before starting a cost-optimized custom design. This OEM subsystem trend has already occurred in many areas. Liquid crystal display (LCD) subsystems are one example – a display subsystem may have connectors, the LCD, a backlight inverter, and special bus interfaces all on a single board ready to connect to other subsystems. This trend applies to measurement and control as well.
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Table 1. National Instruments offers a broad assortment of measurement and control solutions for OEM devices. Visit ni.comand search on keywords from the “Machine/OEM Equipment” column above for more information.
Measurement-Ready OEM Subsystems Defined
One example of a measurement-ready OEM subsystem used in production equipment is the National Instruments LabVIEW FPGA and NI CompactRIO platform, which delivers the following features:
• High-level graphical system design software for application development
• Application programming interface (API) for measurement and control
• Off-the-shelf measurement and control I/O modules
• Open architecture for custom I/O module designs
• Easy networking and interfacing to other embedded subsystems
• Advanced signal processing and control features
• Small size that runs on DC voltage
• Low price
Figure 1. The NI CompactRIO hardware platform is an FPGA-based, reprogrammable measurement-ready OEM subsystem.
The CompactRIO platform uses a field-programmable gate array (FPGA) as the core processor and a 32-bit processor for signal processing, supervisory control, and networking. With an FPGA, a design engineer can program electrical connections for a specific application without paying tens to hundreds of thousands of dollars to have the application-specific integrated circuit (ASIC) manufactured in mass quantities. Another benefit of the FPGA versus an ASIC or custom circuitry is that an FPGA can be reprogrammed. With NI LabVIEW FPGA, engineers can program the FPGA graphically, greatly simplifying development. The CompactRIO hardware platform provides direct access to the I/O circuitry of each plug-in, hot-swappable I/O module. Each module includes built-in connectivity, signal conditioning, conversion circuitry (analog-to-digital or digital-to-analog), and an optional isolation barrier. Using this low-cost, open architecture, developers can make their own custom modules. Today, National Instruments offers more than 30 I/O modules, including general-purpose I/O, machine monitoring, strain, power drive, and Controller Area Network (CAN) modules. Several third-party vendors, including Freescale, offer more than 20 I/O modules for CompactRIO.
Jump-Start Embedded Designs
Shorter product life cycles put greater pressure on OEM developers to bring new designs to market faster. Figure 2 illustrates how an FPGA-based measurement-ready OEM subsystem such as CompactRIO gets an application to market faster, while custom designs take longer but may target higher-volume applications. Developers who design at the component level often overlook the benefit of using an easy-to-program sub-system that is field-upgradeable. A reprogrammable FPGA can add new features to an initial design, reach new customers, and extend the product’s time in market.
Figure 2. FPGA-based measurement-ready OEM subsystems such as CompactRIO get lower-volume OEM applications to market faster; custom designs take longer but target higher-volume applications.
Design, Prototype, and Deploy
Using measurement-ready subsystem hardware and graphical system design software, OEM developers can design, prototype, and deploy solutions faster than ever. The design process starts with simulating and evaluating design options using LabVIEW for signal processing, control design, state control, and debugging. The next step is to prototype the subsystem with the other embedded subsystems, in which developers validate and perform system tests on the design. Finally, developers deploy the system and perform field testing. All of these steps can be simplified using LabVIEW FPGA.
Many NI customers, such as General Motors, Boston Engineering, and FEO Medical, report that LabVIEW increases their productivity and helps them design systems in a third of the time of past designs.
Figure 3. Product and service and support life cycle requirements for OEM designs can vary significantly.
Subsystem Service, Support, and Part Management
Other key issues for OEMs are service commitments and part management. Product life cycles for OEM devices can vary from just a few years to a decade, as shown in Figure 3. The subsystem supplier must be able to deliver the service and equivalent functionality needed over the lifetime of the OEM design. Often service, support, and part-management cost considerations are overlooked because hardware prices are easier to calculate.
Finally, building an OEM device using a measurement-ready subsystem offers several inventory and part-management advantages. OEM developers essentially outsource the negotiation and acquisition of long-lead-time parts to the subsystem supplier, who assumes responsibility for the scheduling and component availability risks associated with the subsystem. It is also simpler and more cost effective for the equipment maker’s manufacturing group to manage parts. There is only one subsystem part rather than hundreds of components on the bill of material.
System Engineering versus Custom Design
Taking advantage of measurement-ready subsystems can save time to market and lower part-maintenance issues without sacrificing performance. New measurement-ready subsystems such as CompactRIO that work with LabVIEW are simplifying the development of machines, industrial equipment, analytical instruments, and medical devices.
Director of Measurement and Control
Learn more about NI measurement-ready OEM capabilities.
This article first appeared in the Q3 2006 issue of Instrumentation Newsletter.
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