TECH FOCUS: GIGE VISION
Keep pace with Gigabit Ethernet
Bob McCurrach, director of standards development at AIA, updates on the progress being made in GigE Vision
S
ince its release in 2006, GigE Vision has seen incredible market adoption and this is no accident. With Ethernet
ports native to all PCs, the prevalence of Ethernet networks, easy networking of multiple cameras, and cable lengths to 100 metres, GigE Vision has been an easy choice for many users. But the story gets better: GigE Vision is scalable to all speed grades of Ethernet, so, as computer chips get faster, GigE Vison will adapt to take advantage of the opportunities that greater speed makes available. GigE Vision technical committee chair,
Eric Bourbonnais from Teledyne Imaging, commented: ‘As people realised the potential of GigE Vision based on version 1.2 of the standard, multiple requests came to the technical committee to extend the capabilities of the standard.’ As a result, GigE Vision 2.0 introduced an extended GigE
Vision streaming protocol (GVSP) packet to allow for future expansion. GigE Vision 2.0 uses this new packet format to transport compressed images and non-raster scan image output. Additionally, GigE Vision 2.0 introduces IEEE 1588, precision timing protocol support, which enables users to trigger multiple devices near simultaneously (sub micro-second accuracy) across the network using action commands, or gives a common time stamp for 1588-enabled devices for processing purposes, for example stitching. Tis greatly extends the utility of GigE Vision’s camera networking capabilities, coordinating multiple cameras with incredible timing precision. For GigE Vision, in general, data is
transported in a container called a block – an image is usually sent in one block. Before GigE Vision 2.1, a block was only allowed to contain one type of data – typically an
image – plus one section of metadata. In GigE Vision 2.1 this limitation was overcome, and a block can be composed of multiple parts, each of which can contain data of different types. Tis allows a multitude of different uses beyond just 3D coordinates. For 3D use cases, all the data related to a scene can be transported in one single block where parts can be sent in parallel, whereas using a block per part would require sending the parts sequentially, which would be less efficient. GigE Vision 2.1 also adds the following:
• It expands the IEEE 1588 profile to include 802.1AS, which is part of the time-sensitive networking (TSN) suite of standards;
• It mandates test features for enhanced interoperability;
• It introduces a mechanical supplement with additional connection options on the device end; and
• It leverages the pixel format naming convention (PFNC) from GenICam.
Te technical committee is currently working on GigE Vision 2.2, which introduces GenDC support. Tis gives similar functionality as that introduced in 2.1, but uses a standard GenICam container format. GenICam is a standard hosted by the European Machine Vision Association, which started as a generic camera control (GenICam) layer common among all the standards. It is composed of a number of different
32 IMAGING AND MACHINE VISION EUROPE DECEMBER 2019/JANUARY 2020
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