Schlumberger recently requested Aberdeen Control, who partnered with Bosch Rexroth, to build nine control systems for use on offshore oil rigs. They used a PLC to control the DDL field bus LP04 manifold to ensure that the hazardous zone certification requirements were met. The resulting design included Rexroth’s LP04 double 3/2 version valve manifold with integrated DLL field bus and RA14 3/2 valves. For the safe area version, Rexroth’s ED05 pressure regulator and DDL and ED05 sub-base were specified, along with filter assemblies, mounting kit and DDL units and ancillary components. The ED05 products were swapped for ED07 products for the ex-rated system. On the control side, Rexroth’s mini-PLC, the Indracontrol L20, was used with Indralogic firmware. The customised program was developed by Rexroth’s application engineers using the system tool Indraworks with Winstudio lite runtime and editor. Prior to shipment to the oilrigs, the modified control systems were bench tested and then connected to a diesel engine driven pump for full cycling tests. Following the successful completion of the first two installations, more of these control systems are planned throughout 2008.