A conventional electronic linkage depth control system can normally only operate the tractor threepoint linkage. With a semi-mounted plough, this essentially means the rear depth wheel is left to its own devices. Massey Ferguson has developed its Datatronic II to address this particular problem with its Dual Control system. With it switched on, operators can marvel at a semi-mounted plough that can now be made to lift and lower evenly along its full length. But there is more. Dual Control has some ‘brains’ as well. Manfred Neunaber delves deeper