12-10-2015 | | By Oliver Opl
Industrial image processing is one of the key technologies for implementing Industry 4.0. Seamlessly integrating this technology into industrial production systems demands an intelligent and reliable supply of data and power, writes Harting’s Oliver Opl.
Vision systems are being more and more strongly integrated into industrial manufacturing processes, due to the fact that using camera systems to monitor and control adds flexibility to the process and ensures the product quality. To do their job, the systems need stable, high bandwidth data communication and a reliable energy supply. Ethernet offers a uniform communication standard and is winning people over with its uncomplicated, economical and generic usability. In order also to ensure these advantages for image processing, the GigE Vision interface standard, which is based on Gigabit Ethernet, was adopted. The new Ha-VIS eCon Ethernet switches offer a completely integrated solution for data and power transfer in one device while simultaneously reducing the cabling effort and costs, and work perfectly with all camera systems that are based on GigE Vision.
The completely redesigned Ethernet Switch portfolio from Harting comprises more than 200 different models, each tailored for different applications. Two different compact and space-saving housing models guarantee the best possible use of the available space in the switch cabinet. Thanks to their slim design, the switches from the Ha-VIS eCon 3000 family allow a very high packing density on the top-hat rail in the switch cabinet, while the Ha-VIS eCon 2000 switches feature an extremely flat design. The switches show their strength particularly in highly integrated Vision applications with little available space. With data transfer rates of 1000 Mbps simultaneously on all ports and thanks to the support of PoE+, the Ha-VIS eCon series offers functions that allow efficient and future-proof system design.
The eCon 2000 models and also the eCon 3000 Ethernet switches provide a bandwidth of 1000 Mbps Full Gigabit Ethernet (Full GbE) for applications with high data throughput. All switches are based on a non-blocking store and forward switching architecture, and consequently the full bandwidth can be retrieved and guaranteed at all times even when all ports are used. All Full Gigabit Ethernet switches additionally support jumbo Ethernet frames, which can be generated by such sources as camera systems. The GigE Vision Standard uses this technology, which has established itself in the industry.
Power over Ethernet (PoE) enables the transfer of data and power over one cable, the standard Ethernet data cable. Switches that can supply remote devices with power in this way are referred to as PSE (Power Sourcing Equipment) while the remote devices receiving the energy are called PDs (Powered Devices). PoE is an IEEE standard that currently has two different versions: standard 802.3af, which was adopted in 2003 and which allows power transfer of up to 15.4 watts per port, and the current 802.3at version, referred to as PoE+. The latter allows power transfer of up to 34.2 watts. After conduction losses, at least 25.5 watts are available for the powered device.
The next generation of Ha-VIS eCon switches supports the current standard and can provide the full PoE+ output on up to four ports simultaneously. This means that a total of more than 100 watts of power per switch are available for the powered devices. In addition to high resolution intelligent camera systems, devices with very high energy requirements, such as powerful WLAN access points, can consequently be supplied.
The use of PoE switches does not constitute any risk of damage to non-POE remote devices. Before the energy supply is activated, the eCon switch first checks if the connected device allows a supply over PoE and which power class is in use. PoE+ has five different power classes, which differ in the level of power that is needed. It takes just a few microseconds to determine the power class, which guarantees rapid and high availability.
The integration of GigE Vision image processing systems proves to be simple and efficient. There is no longer a need for a separate power supply for the industrial cameras and the supply line is also no longer required. Data and power share the existing Ethernet infrastructure. This reduces the material costs and the installation effort. When Gigabit Ethernet is used in combination with PoE, the full 100m is available when positioning the cameras, which is a crucial advantage. Existing installations can likewise still be used and retrofitted. Additional cameras enable robots to work much more efficiently and perform more complex tasks. Machine vision often allows manufacturing and quality assurance to be combined in one operational step, so that nonconformities can be detected early in the production chain. Going beyond the PoE/PoE+ standard, models from the Ha-VIS eCon portfolio offer the option of an integrated DC-DC voltage converter. In this case, the switches can be supplied with 24 VDC instead of the normally needed 48/54 VDC. This guarantees the use of already existing power supplies and also saves on the cost for a special PoE unit. Special RJ45 connectors for transferring power are not needed, but the user should keep suitability for industrial use and especially for PoE in mind when selecting cabling components and systems. As a specialist for active and passive data network technology in industry, Harting has trimmed its RJ45 components, system cords and cables especially to parameters such as current carrying capacity, temperature range and vibration resistance. These components are specially tested for PoE or PoE+ use and they consequently guarantee the user a long service life and high operational reliability.
Optimised and developed for use in harsh industrial environments, Ha-VIS eCon Ethernet switches allow swift and simple Plug&Play integration of GigE Vision-based image processing systems for Industry 4.0 and consequently the cornerstones for a sighted expansion to existing network infrastructures and equally the setup of new production systems.