The Port of Durban is South Africa’s premier multi-cargo port and, strategically positioned on the world shipping routes, is counted among the busiest ports in Africa, handling over 80 million tons of cargo per annum. As the leading port in the region, the Port of Durban serves as the premier trade gateway between South Africa and her trading partners around the globe and is also the international commercial gateway to South Africa.
The Port of Durban occupies a focal point in the transport and logistics chain with 60% of all South African imports and exports passing through the port. Some of the commodities exported from South Africa via Durban Harbour require special machinery to load them on to vessels.
In 2005, Thyssenkrupp purpose-built a shiploader for the handling of grain and wood chips with respective loading capacities of 1000t/hr and 800t/hr. Operating at Maydon Wharf, the shiploader incorporates a telescopic boom that can be extended from 19 to 31m. Fitted to the boom is a swivelling ‘Jetslinger’ which is lowered into the ship’s hold. Once inside the hold the system can be swivelled and rotated to ensure an even spread of product, vital for the correct balance of the vessel.
Over the years signal cables have been damaged as a result of machine motion, leading to breakdowns. A more reliable wireless system was required to replace the function of the signal cables.
A new ControlLogix® PLC was installed on the system which had to communicate with the system’s existing Allen-Bradley® SLC™ 500 PLC over EtherNet/IP™. It was decided to incorporate an Ethernet radio system from ProSoft Technology to handle the communication traffic between the two PLCs. ProSoft’s RLX2-IHNF-W weatherproof radios presented the perfect solution due to their ruggedness and ability to withstand the extreme environment. The radio has an operating temperature range of -40°F to 167°F (-40°C to 75°C) and features an IP66/67 rating. The radios were paired with MIMO (multi path) antennas at one end and three separate omni-directional antennas mounted at the other (spacing at 120-degree points), to ensure that full radio signal strength would be maintained throughout the full 360-degree rotation.
The installation of a ProSoft AN-X2-AB-DHRIO gateway provided the solution to the previously installed SLC5/04 PLC which was not equipped for EtherNet/IP communications. Designed for interfacing Allen-Bradley’s DH+™ and Remote I/O™ protocols to EtherNet/IP, the ProSoft AN-X2-AB-DHRIO gateway allows the transfer of communications from the SLC5/04 (equipped with a DH+ communications port) via the Ethernet radios.
Commenting on the system’s performance since installation, Thyssenkrupp’s Project Engineer, Gerhard Kamffer, says, “The entire implementation of the AN-X2-AB-DHRIO gateway was extremely easy, which was made even simpler by the user-friendliness of the ProSoft radios, which work extremely well over the short communication distance. A great added benefit was the fact that the SLC controller can also be accessed through Ethernet for programing purposes. The toughness of the radios ensures smooth operation in this harsh bulk handling application, and six months into the implementation process, no problems have been experienced with the system.”