SSD LINK systems were very popular on a number of continuous process machines through the 80s, 90s and into 2000. The LINK system used block programming via software called DSD and connected multiple drives on a fibre optic network. The software was function based so traffic was kept to a minimum allowing very fast processing times – far greater than any of the PLCs of the time. The software also incorporated a number of special blocks that made specialist functions such as winding very straight forward. These blocks could be specially adapted to maximise the performance of the machine.
The LINK system has been obsolete for a number of years and maintaining these systems has become increasingly difficult. Parker has developed a replacement system called LINKNET which allows these systems to be updated and future proofed. LINKNET is an Ethernet based platform and utilises all the features of DSE software to make the transition as straight forward as possible. Parker is working closely with a number of systems integrators to provide the best access and support for the new LINKNET equipment and this can be used on a diverse range of industrial automation applications.
Using an open protocol such as Ethernet allows maximum flexibility for supporting additional equipment such as HMIs and data collection equipment as well as keeping the data transfer speeds at a rate suitable for process machines. In a production environment the benefits in terms of installation, configuration, ease-of-use and longevity are paramount. This represents a significant yet sensible evolution rather than a revolution meaning that implementing newer approaches is not an especially testing or disruptive experience for the end user.
The benefits of switching from fibre optics to Ethernet were well demonstrated in a recent upgrade project undertaken by Oracle Drive Systems – a Parker systems integrator based in Batley, West Yorkshire. Established in 2004 by former employees of what is now known as Parker SSD Drives, the company has built-up significant expertise in designing, implementing and upgrading control solutions for companies using drives in industrial environments.
The end customer in question – Skymark Performance Films – is a provider of cast and blown film co-extrusions and other printed, laminated and complex conversions. The company’s products serve a range of sectors including food & drink, hygiene & medical, stationery and textiles. Production is in volume and often on a ‘just in time’ basis putting emphasis on reliable, flexible and controllable manufacturing processes.
Prior to upgrade by Oracle, the Parker variable speed drives used by Skymark were controlled via an SSD LINK fibre-optic system that, although extremely reliable, had been in place for over 20 years and was approaching obsolescence with spare parts increasingly difficult to source. For the upgrade, Oracle opted for Parker’s newer LINKnet Ethernet based version of the popular, proven, but out of date SSD LINK system. LINKnet uses standard CAT-6 cable and needs no external power supply when used as a plug-in module for Parker’s AC690 or DC590 drives. This made the retrofit relatively straightforward and allowed a largely ‘click and connect’ upgrade process, minimising the impact on Skymark’s production facility. The LINKnet Ethernet based system dispenses with the need for repeaters and uses the same popular DSE software as the system being replaced. This means that users benefit from a simple ‘drag and drop’ interface and many pre-engineered macro and function control blocks in LINK’s extensive software library to allow straightforward design of systems.
Oracle has addressed numerous other applications with similar upgrades to Ethernet based control using Parker’s LINKnet system. As well as avoiding the issues associated with an aged approach with diminishing popularity, the relatively straightforward adoption of LINKnet can deliver multiple benefits in terms of control, versatility and reliability well into the future.
Commenting on the use of LINKnet and its relationship with Parker Hannifin, John Mullins, Oracle Drive Systems said: “The Skymark application provided a great example of the simplicity and advantages of using LINKnet to control and manage the operation of drives in an industrial environment. It also underlined the importance of our close working relationship with Parker as a systems integrator to help expedite the project.”
Commercial Manager – Intelligent Controls Business Unit
Electromechanical & Drives Europe, Parker Hannifin