Machine Vision Standards

Machine Vision plays a fundamental role in industrial inspection, providing advantages in quality control, process speed or automation. Its implementation in production lines is a reality prevalent in many productive sectors.

In this context, standardization is essential to ensure compatibility between systems. An example: say we have a production line in which we have invested heavily in developing and deploying a machine vision system for quality inspection. The system has cameras placed at multiple points in the line. Our solution is bringing us great competitive advantages. Suddenly, one of the cameras fails. “Don’t worry; I will call the provider to ask for replacement… Discontinued? What? Stop the line and redesign the system?…” This situation does not seem a very nice one, but fortunately we can prevent it.

When analog cameras dominated the industry of Machine Vision, communication interfaces were standardized. However, the introduction of digital cameras yielded a disjunctive in communication interfaces between the principal manufacturers.

The first industry standard for digital cameras, and one of the most popular, was Camera Link. It provides a parallel connection, which allows high transfer speed. However, Camera Link has some limitations like the high cost of connectors and camcorders or a maximum wire length limited to 10 meters. Another integration problem is that the standard defines only the transmission protocol, but not the control protocol, so it lacks of compatibility between manufacturers. Another communication interfaces that are present in the market are USB or IEEE1394-Firewire, but both its level of standardization and its commercial impact were very low.

In 2006 the GigE Vision standard was introduced, providing a framework for both the transmission of high speed video and the control protocol over Ethernet networks. The standard is supported by the principal companies of machine vision equipment and it is driven by the Automated Imaging Association (AIA). Cameras with GigE connectivity have a number of advantages derived of adopting the standard Gigabit Ethernet:

• Speeds up to 100 MB/s with standard network adapters.
• CAT-6 wires, which are inexpensive in comparison with other technologies. It allows lengths up to 100 meters without the need of repeaters, facilitating the distribution and direct replacement of analog cameras.
• Use of standard network hardware, allowing multiple configurations and remote processing.

In Gradiant, we are working actively in the dissemination of new Machine Visión standards for the industry, encouraging their use in project development and conducting training sessions as the “Visión Artificial Aplicada a la Industria” course. This seminar, taught by INFAIMON and hosted in CITEXVI on Thursday October 20, has brought these technologies to more than 45 professionals. The keys to managing a Machine Vision system and the latest technologies within the industry have been presented.