Standard camera interface for data acquisition
In the field of measurement technology, traditional tools like current meters, voltage sensors, or strain gauges are often top of mind. These days, however, cameras have also become indispensable in various applications, ranging from crash tests and surveillance via bird’s-eye view to monitoring turbines in hydroelectric power plants.
The technology used in these applications must fulfill strict standards, deliver real-time data with high accuracy, and be easy to handle. One interface that excels and is widely accepted in the industry is GigE Vision. In this blog post, we will explore GigE Vision, highlight its key features, and review alternative interfaces that might better suit your specific needs. Finally, we discuss what cameras and interfaces DEWETRON offers.
What is GigE Vision?
GigE Vision is an interface standard founded in 2006 by a consortium of companies designed to offer a simple yet powerful solution for imaging applications. The goal was to develop a standard that integrates seamlessly with common hardware and provides high data throughput. This objective has been successfully achieved, making GigE Vision a key player in modern imaging technology. Today, the Association for Advancing Automation oversees further development and management of the GigE Vision standard.
Fig. 1: GigE Vision Logo
How does it work?
GigE Vision builds on the widely adopted Gigabit Ethernet standard, utilizing the TCP/IP and UDP protocols for data transfer. The standard is a cornerstone of modern network infrastructure and significantly simplifies installation and integration, as most modern systems already support these technologies. The GigE Vision standard comprises four main components, each serving a specific function:
- GigE Vision Control Protocol (GVCP)
GVCP is responsible for controlling and configuring devices, specifying stream channels, and managing the transmission of image and configuration data between computers and cameras. - GigE Vision Stream Protocol (GVSP)
GVSP defines the data types and transmission methods used for sending images across the network. - GigE Device Discovery Mechanism
This mechanism enables the detection of cameras within the network by obtaining their IP addresses. - XML file
Based on the GenICam standard, this file provides access to camera data and images, standardizing communication and ensuring compatibility across different devices.
What are the key features of GigE Vision?
GigE Vision provides numerous advantages, making it a preferred choice in many imaging applications:
- Versatility: GigE Vision is available in various configurations to meet different performance requirements, including standard GigE, Dual GigE, and 10 GigE versions.
- High-speed: GigE Vision enables rapid, real-time transfer of large image files with minimal latency. It supports data rates of up to 1 Gbit/s for standard GigE Vision, 2 Gbit/s for Dual GigE Vision, and up to 10 Gbit/s for 10 GigE Vision, depending on the version used.
- Extended reach: The standard supports uncompromised data transfer over distances of up to 100 meters, providing flexibility in camera placement without signal degradation.
- Standardized connectivity: Utilizing low-cost CAT5e or CAT6 cables and standard Ethernet connectors, GigE Vision ensures easy and reliable connectivity, leveraging widely available networking components.
- PoE (Power over Ethernet): Many GigE Vision devices support Power over Ethernet, enabling both data and power transmission via a single Ethernet cable.
- Cost-effective: By using standard hardware and readily available cables, GigE Vision reduces overall system costs and simplifies integration.
- Scalable: The technology is highly scalable, keeping pace with the rapid advancements in Ethernet technologies, allowing for easy upgrades and expansion as network demands grow.
What are the alternatives to GigE Vision?
While GigE Vision is a popular choice for high-performance imaging applications, several other standards and technologies offer viable alternatives depending on specific requirements such as data rate, cable length, cost, and application environment. In the following, we describe the key features of alternative imaging standards:
USB3 Vision
USB3 Vision is based on the USB 3.0 standard and is designed for high-speed data transfer over USB cables. It offers a high bandwidth of up to 10 Gbit/s, and its simple plug-and-play setup makes it widely supported across many devices. However, the maximum cable length is typically limited to around 3-5 meters, although this can be extended with active cables or repeaters.
Camera Link
Camera Link is a high-speed serial communication protocol specifically developed for machine vision applications. It provides low latency and data rates of up to 6.8 Gbit/s making it a viable choice for high-speed and high-resolution imaging tasks. The system requires more complex and expensive cabling, and the maximum cable length without repeaters is generally limited to 10 meters.
Camera Link HS
Camera Link HS (High Speed) is built upon the original Camera Link standard but offers significantly higher data rates, enhanced flexibility, and greater scalability. It supports data transfer rates of up to 10 Gbit/s per lane, with multiple lanes possible for even higher throughput and cable lengths of up to 300 meters using fiber optic cables.
CoaXPress 2.0
CoaXPress 2.0 is the latest iteration of the CoaXPress standard, a high-speed point-to-point serial communication protocol utilizing coaxial cables. This version substantially enhances data transmission capabilities, supporting rates up to 12.5 Gbit/s per cable, compared to 6.25 Gbit/s in the previous version. CoaXPress 2.0 allows the use of multiple cables in parallel, further increasing total data throughput. It supports cable lengths up to 100 meters at lower data rates and approximately 30 meters at the highest data rate.
FireWire (IEEE 1394)
FireWire (IEEE 1394), once popular in industrial imaging, supports moderate data rates and allows both data and power to be transmitted over a single cable. It is relatively simple to set up and supports peer-to-peer connections. However, FireWire has largely been surpassed by newer technologies leading to a decline in its use.
Fig. 2: Max. Bandwidth of various camera interfaces in comparison;
*value for a single cable – higher bandwidth achievable with multiple cables.
What cameras do we offer at DEWETRON?
At DEWETRON, we specialize in manufacturing modular and high-precision measurement systems. Alongside our signal acquisition and conditioning solutions, we offer a variety of components and sensors, including a selection of Allied Vision Alvium cameras.
Fig. 3: CAM-ALVIUM-1800-U-040
This selection includes various high-resolution USB3 Vision and GigE Vision cameras with frame rates up to ~290 fps. All devices have a compact design and can easily be integrated into any vision system.
Each model supports external triggering and provides real-time image transmission. When paired with our OXYGEN measurement software, you benefit from perfectly synchronized video data, enhancing your measurement applications. The following image illustrates a live video measurement integrated into the OXYGEN measurement screen. It shows synchronized footage from a windscreen camera during an on-the-road power measurement.
Fig. 4: OXYGEN measurement screen with integrated live video
