GigE Vision and GenICam Standards
GigE Vision standard was published in 2006 under AIA (Advanced Imaging Association). It defines set of communication protocols for industrial cameras using (Gigabit) Ethernet as its transport media. The goal of the standard was to reach high degree of interoperability between individual manufacturers - particularly between the cameras and the software libraries.
For the first time the machine vision cameras connect automatically to all major image processing libraries without need to write and maintain dedicated plugins or drivers.
Main advantages of GigE Vision against "competing" technologies are:
Gigabit Ethernet infrastructure is readily available in most current systems and is well known.
Plug&play, support of GenICam standard.
Sufficient bandwidth for most of current camera designs. Larger bandwidth is offered only by Camera Link, but after arrival of the 10G Ethernet even this will not be true.
Cable length up to 100 meters without regeneration, with switches the length is practically unlimited.
Number of cameras available in the system is practically unlimited.
Wide spectrum of network topologies enable to build specific systems.
Cost savings thanks to utilization of cheap, off-the-shelf equipment such as network cards (instead of specialized frame grabbers), standard network cables, etc. Total costs can compete even with analog systems.
GigE Vision is actually set of protocols built on top of UDP/IP, allowing to achieve maximum possible performance. Its main components are:
GVCP - GigE Vision Control Protocol, carrying the camera control related communication, particularly reading and writing camera registers
GVSP - GigE Vision Streaming Protocol, carrying the image data provided by the camer
Bootstrap registers - set of mandatory registers controlling the most essential camera parameters, allowing to identify the camera and establish the connection. Additional, device specific registers can be defined by means of the GenICam standard.
For information, please visit: www.gigevision.com
The GenICam standard was published in 2006 under EMVA (European Machine Vision Association). Its main idea is to provide a unified application programming interface (API) to the users of machine vision cameras. Sitting on top of the individual transport technologies (such as GigE Vision), it enables an easy integration of individual components, such as cameras and image processing libraries.
GenICam is independent on the transport layer technology (besides GigE Vision, it can be implemented also with cameras featuring USB or other interface). GenICam consists of three main modules, GenApi, SFNC, and GenTL.
GenApi (GenICam Application Programming Interface) is a "basic building block" of GenICam. It allows to describe complete camera functionality using an XML configuration file, usually stored directly on the camera, which further simplifies the automatic configuration process. Reading and interpreting this file, the software library gets automatically access to complete camera functionality.
SFNC (Standard Features Naming Convention) is kind of superstructure on top of GenApi. It defines a convention for naming features typical for machine vision cameras. SFNC defines an universal camera model, which might be implemented by most of the cameras on the market. Thanks to this convention, generic applications, libraries, but also the users can comprehend compliant camera without detailed study of its documentation.
GenTL (GenICam Transport Layer) defines interface for acquisition of image sequences (or additional non-image data) independently on the transport layer technology and platform (operating system, programming language, etc.). It allows to enumerate and identify the devices (cameras) connected to the system, control access to them from individual applications, configure them (by means of GenApi), and completely control the acquisition itself.
For more information, please visit: www.genicam.org