What Is NI Vision?

For more than 30 years, National Instruments has been a leader in measurement and automation, providing powerful hardware platforms and flexible software for engineers and scientists around the world. More than a decade ago, NI added machine vision to its product line. The NI machine vision platform includes hardware ranging from plug-in devices for PCI and PXI systems to image processing on the sensor itself with the NI Smart Camera. Software options include image acquisition software to acquire images from thousands of cameras, a world-class image processing library, and a configurable interface for industrial machine vision applications.

Why Machine Vision?

Engineers and scientists use machine vision instead of other traditional sensors and measurement tools because it offers unique abilities not found in many traditional tools. Consider, for example, a conveyor with items traveling at 300 parts per minute, and you want to take a simple width measurement of the items coming down that production line. With traditional tools, you need to use a caliper tool to get an accurate reading. But you are not able to effectively measure every part, so you need to use sampling and measure every hundredth part, giving your system 20 seconds per part to remove the object from a conveyor, measure, and replace the item. There is also the risk of damaging the object as the operator or robot arm tries to remove and replace this piece on the conveyor.

With machine vision, you can inspect every single part instead of randomly sampling and just hoping that the rest of the parts are OK. Because machine vision tools are nondestructive, you ensure that none of the parts are damaged in the measurement process  while achieving extremely high-accuracy measurements.

Figure 1. Examples of Machine Vision Applications

Many other tasks cannot be performed effectively or at all with traditional sensors. Verifying labels, counting pills going into bottles, monitoring a speeding bullet, reading or verifying text on packaging, reading 1D and 2D bar codes, and many other applications are all simple tasks if you have flexible machine vision software and hardware powerful enough to perform the measurements. You can implement many other applications using traditional tools, but machine vision makes these tasks much easier. For example, with traditional tools, you would monitor the condition of a pressurized tank for temperature irregularities by connecting thermocouples in an array all over the tank and observing each thermocouple. With machine vision, one infrared camera could watch the entire tank, and you could use machine vision software to detect exact temperatures on all points of the tank instead of just a few locations in an array.

NI Vision Hardware

NI vision hardware provides a variety of options for different application needs, all powered by the same flexible software. Many engineers and scientists who want to include vision data with their measurements prefer the high speeds and synchronization options of plug-in NI frame grabbers. NI offers plug-in boards that work with Camera Link (the highest bandwidth currently available in a standard camera interface), IEEE 1394, GigE Vision, analog, and parallel digital buses. For information on each of these buses, including the advantages of each, visit Choosing the Right Camera Bus. For PC buses, NI vision hardware supports PCI Express, PCI, and PXI.

Figure 2. Plug-In NI Frame Grabbers

Other NI machine vision options include two rugged, industrial solutions – the NI Compact Vision System and the NI Smart Camera. The NI Compact Vision System offers direct connectivity to up to three IEEE 1394 cameras and features an onboard processor as well as a field-programmable gate array (FPGA) for precise timing and custom digital I/O interfaces. Like IEEE 1394 frame grabbers from National Instruments, the NI Compact Vision System supports any DCAM-compliant machine vision camera. NI offers three versions of the NI Compact Vision System with varying onboard memory and processor speed. Please see the NI Compact Vision System page for more information.

Figure 3. The NI Compact Vision System (left) and the NI Smart Camera are two rugged, industrial machine vision solutions from National Instruments.

The second industrial solution for machine vision is the new NI Smart Camera, which combines a high-quality CCD image sensor and a PowerPC processor in one rugged package designed for use in industrial environments. Smart cameras are ideal for many industrial applications where ease of use and ruggedness are very important. Visit the NI Smart Camera page for video tutorials, specifications, and other details.

NI Vision Software

National Instruments offers three software products for machine vision. NI Vision Acquisition software provides drivers and function calls to acquire images from thousands of different cameras connected to NI frame grabbers, or for IEEE 1394 and GigE Vision cameras connected to a standard port on a PC, PXI system, or laptop. For a list of supported cameras, visit the Industrial Camera Advisor. NI Vision Acquisition software is included with all NI vision hardware and the other two software products, the NI Vision Development Module and NI Vision Builder for Automated Inspection (AI).

The Vision Development Module is a powerful machine vision processing library with functions including edge detection, particle analysis, optical character recognition and verification, 1D and 2D code support, geometric and pattern matching, and color tools. This module works with NI LabVIEW and LabWindows™/CVI software, as well as C, C++, Microsoft Visual Basic, and Microsoft .NET. Because of this, you can easily add machine vision to your existing applications without changing programming languages. You also can use Vision Development Module synchronization functions to synchronize with motion or data acquisition measurements.

Figure 4. NI Vision Development Module in LabVIEW (left) and NI Vision Builder AI

If you do not want to program your vision applications, you can use Vision Builder AI, a menu-driven, configurable interface for machine vision. This application is based on an easy-to-use state diagram model, allowing branching or looping based on inspection results. With more than 40 powerful machine vision functions and steps for communication with expansion I/O such as programmable logic controllers (PLCs), programmable automation controllers (PACs), and human machine interfaces (HMIs), Vision Builder AI is an ideal development environment for many industrial applications. For demos, white papers, and a free download of this software, visit the NI Vision Builder AI page.

Unmatched Scalability

The NI vision hardware platform ranges from PCI- and PXI-based systems to NI Compact Vision Systems to the sensor itself with the new NI Smart Cameras. The Vision Development Module and Vision Builder AI  support this entire range of hardware. This means you can design and prototype your machine vision algorithms using an off-the-shelf machine vision camera connected to an NI frame grabber and deploy that same application to an NI Smart Camera with minimal changes to your LabVIEW code or Vision Builder AI inspection. The NI vision hardware platform also offers upward scalability if your system requirements change and you need more processing power or higher throughput than your original platform provides. You can simply change to a different option within the NI vision hardware platform and continue to use your existing code.

The mark LabWindows is used under a license from Microsoft Corporation.

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