The two-wire variant of the modular telecontrol system MFW was especially designed for data transmission on electrically isolated two-wire cables. There is no need of laying special cables in the ground. The common, often existing signal cables can be used for data transmission. There are no specific cable quality requirements, so that even on very old cables transmission is often possible. Only the maximum loop resistance, which results in the sum of the resistance of each single conductor, has not to be exceeded. The noise immunity of the data transmission on the two-wire line is very high. The cable routing can be done either in line, star or branch system. In addition, the transmission can be encrypted when used, for example, in critical infrastructures. The distance between 2 stations can usually be up to 20km.