The HSLink advantage now applied to improving machine vision

Simultaneously send and receive data with HSLink technology
Pioneered by DALSA Corporation

What is HSLink?
HSLink is a high-speed file transfer protocol which allows a list of files to be sent, over a link, in both directions until each side of the link is satisfied. However, HS/Link is not merely a bi-directional set of rules, it is also a very fast protocol for normal downloading and uploading that incorporates some new technologies to make file transfer more reliable - , the protocol being responsible for protecting the files against corruption during transfer and taking measures to correct any errors that are detected.

How does the new HSLink technology?
The intention of the new protocol is to present a more complete specification for industry's use as the next-generation machine-vision interface.

Designed as an upgrade for CameraLink and incorporating its key concepts, the new protocol enables smaller, lower-cost cameras and frame grabbers, connected over simple network topologies all-the-while considering data reliability as a key design requirement for HSLink development.

Using only a single cable while providing very high camera bandwidths, the new standard offers a low-cost data forwarding mode to reduce image processing costs and user-ease by achieving plug-and-play convenience. Note: HSLink is ideal at any bandwidth because it delivers a small imaging head, reliable and low-cost data transmission technology and ease-of-use with standardised triggering and Genlcam compliance.

Why is HSLink an improvement on the previous standard??
The interface has taken the key strengths of Camera Link™ (an industry-specific connectivity solution), while using broadly-used, off-the-shelf components with development road maps for increased performance. This protocol will have a long service life and is designed to ensure longevity in the marketplace with an expected life cycle 10 - 20 years.

As well, new features and functions have been added to meet customers' present and future needs.

How does HSLink work? To gain a better understanding of HSLink, Figure 1 provides an overview of HSLink topology from a camera perspective, and Figure 2 provides an overview of HSLink from a framegrabber perspective. Note: the camera perspective and the framegrabber perspective are very similar and use the same technology, the framgrabber using it in reverse order.
The HSLink IP Core takes in Camera Link signals and priority manages trigger, GPIO image data and configuration data and sends this information to the PHY via GMII (Gigabit Media Independent Interface) and/or NBI (Nine Bit Interface). The HSLink IP core ensures guaranteed data delivery and simplifies design implementation in both framegrabbers and cameras. Multi-vendor PHYs, that operate on NBI and GMII, are available that serialize and de-serialize the data transmitted over the cable medium. For low bandwidth applications (<300Mbytes/s), Infiniband (IBx1) or Coax cabling offers a low cost solution. For applications up to 2100Mbytes/s, a single CX4 cable is used, which significantly reduces the size and number of cables required compared to today’s machine vision standards, and still delivers 15m transmission distances.
Figure 1: (above) Topology of HSLink from a Camera perspective	Figure 2: Topology of HSLink from a Framegrabber perspective
As seen in both diagrams, the HSLink IP Core takes in input signals that the machine vision industry understands from the CameraLink standard. On the camera side, the HSLink IP Core takes these inputs and sends them via GMII (Gigabit Media Independent Interface) and/ or NBI (Nine Bit Interface), and ensures guaranteed data delivery. The PHY (SERDES chip) takes the information it receives, serializes it, and transmits it to the framegrabber via cabling. Depending upon the camera bandwidth the PHY sends the information in three potential formats named by the subcommittee as NBILink, GMIILink and MixedLink. Each format has its own associated cabling and protocol

Adept Electronic Solutions are "The Machine Vision and Imaging Specialists" and distributor of DALSA Machine Vision products in Australia and New Zealand. To find out more about DALSA or any machine vision product please email us at: adept@adept.net.au or call us at Perth (08) 92425411 / Sydney (02) 99792599 / Melbourne (03) 95555621 or use our online contact us page.