The History of the RedFox Ethernet Switch
RedFox industrial is an off the shelf product, but its architecture and firmware are tried and tested in some of the toughest environments imaginable. The RedFox concept has already been used on board trains, in military vehicles, on aircraft and on the seabed. No ordinary switch could have been used in these applications.
High Altitude Airliner Testing
Modern airliners have to undergo rigorous testing prior to delivery and use by the airlines to transport passengers.
Test data must be collected and stored on thousands of hours of test flights in order to verify that the aircraft is safe to use. The Boeing Corporation selected Ethernet as the high speed network to allow all this data to be collected during its development of the 787 Dreamliner.
To be used in this application Redfox had to be tested to RTCA DO-160E - "Environmental Conditions and Test Procedures for Airborne Equipment" and D6-16050-5 Rev B - "Electromagnetic Interference Control Requirements for composite Airplanes". These tests meant that the switch had to operate up to altitudes of 16000 m and meet comprehensive vibration specifications.
Ocean Floor Monitoring
When Cameron Subsea required an Ethernet switch that could be built into its subseacontrol modules the RedFox was the best solution.
The modules were there to control and monitor seabed pumps used for extracting oil and gas at depths of up to 3000 m. The biggest area of concern for a switch in this environment was vibration and RedFox had already been proven to meet the highest specifications. Another advantage that RedFox offered was that it could be configured with fibre ports allowing communications over 80 km and also support redundant protocols. Both points critical with the remoteness of the installations.
The Ethernet Train
Regional trains in Germany and the Netherlands are currently being delivered by Bombardier with an on board Ethernet network. This is the world's first example of Ethernet being used for train control data management. Train control has traditionally been via a TCN (Train Control Network) however using Ethernet for this network will reduce cost and increase functionality. For this innovation, Bombardier has chosen Westermo's RedFox railway switches. 400 units have been supplied for the first projects.
Up to now, Ethernet has been used on board trains only for CCTV (Close Circuit Television), passenger information systems and entertainment. Traditionally different train subsystems used dedicated networks. For train operation, a railway-specific network called TCN was used. Bombardier Transportation has developed a new system where Ethernet now manages all of the train's on board equipment. In the first projects, the old and new networks - Ethernet rings and TCN - will coexist, but Ethernet will fully replace the TCN in two or three years. The Bombardier Transportation system will be the first to integrate all the intelligent devices onboard into one Ethernet network. The first train projects without any TCN - relying solely on Ethernet networks - are already in the design phase.
For the regional trains already operational in Germany and the Netherlands, the Ethernet network is able to determine the composition of a train e.g. what kind of coaches constitute the train, in which order they are coupled together, and in what direction they run (to be able to open the correct set of doors, etc) while the TCN is still used for some local subsystems.
"We have a project where the TCN will be kept only for localised subsystems whereas train-wide communication will be carried out on the ETB (Ethernet Backbone). This is the next step on the way to a totally Ethernet train. The network will ultimately carry all the data needed for train operation, surveillance and passenger information. All systems except signalling and Internet access will be managed through this Ethernet network." Says Klas Englund, TCMS Product Manager at Bombardier Transportation Sweden.
There are between 2 and 4 switches in each carriage and up to 8 carriages making up a complete train. To this point over 400 switches have been delivered. The advantage of using Ethernet switches is that there is no limit to how many can be cascaded down the length of the train ensuring that no consideration ever needs to be made to the length of the network.
Reduced costs and greater flexibility were the two main reasons to use Ethernet networks on board trains. Hardened Ethernet solutions already existed offering the high bandwidth required for audio and video services at a reasonable cost whereas a new rail-specific network would have been expensive.
"There were many candidates for cooperation on this product that will probably become the new train standard. The main reasons for selecting Westermo were, firstly, that they had an interesting and promising concept with their RedFox product line which could serve as a platform for implementation of our add-on functionality. Together we saw the possibility for adaptation to our needs and the integration of own software functions into the products. Westermo also demonstrated an open mind about the way to cooperate, and a strong involvement in customisation for rail needs." Adds Mr Englund.
A new front panel was developed by Westermo with M12 connectors. Adjustments have also been made to meet the railway specific standards regarding EMC (Electromagnetic Compatibility) EN50155 and other environmental requirements. On Bombardier's side, engineers have developed a custom application that has been integrated into the switches.
"In the future Westermo products will be on all types of rail vehicles from trams to locomotives," concluded Mr Englund.
