A scanning system, for moving a first and a second set of sensor electronic devices between a first end and a second end along a main scanning direction, which comprises: a first mobile carriage which supports a first scanner head in which the first set of sensor electronic devices is housed wherein, for at least a plurality of the sensor electronic devices, each has a sensor input; a first set of control electronic devices that is located in a module remotely from the first scanner head and which is separated by a distance of at least 50 meters from the first scanner head, wherein for at least a plurality of the control electronic devices, each has a control output; a control multiplexer that is coupled to the plurality of control electronic devices and which is located in the same module containing the first set of control electronic devices and adapted to receive input signals therefrom and to provide control signals of the plurality of control electronics for transmission through a first wire; a sensor de-multiplexer that is coupled to the plurality of sensor electronic devices and adapted to receive the control signals from the first wire and to provide sensor signals to selected sensor electronic devices to which the sensor de-multiplexer is coupled; a ground wire that connects the control multiplexer and the sensor de-multiplexer; means for driving a mobile carriage (28, 30, 32, 34) along the main scanning direction which has a distance of at least six meters; a second set of sensor electronic devices, that is housed in a second scanner head that is supported by a second mobile carriage, wherein for at least a plurality of these sensor electronic devices, each has a sensor output; a second set of control electronic devices, that is located in a module remotely from any scanner head (2,18) and which is separated by a distance of at least 50 meters from any scanner head (2,18), wherein for at least a plurality of these control electronic devices, each has a control input; a sensor multiplexer that is coupled to the plurality of sensor electronic devices of the second set and adapted to receive input signals therefrom and to provide sensor signals of the plurality of sensor electronic devices of the second set for transmission through a second wire; and a control de-multiplexer that is coupled to the plurality of control electronic devices of the second set and which is located in the same module containing the second set of control electronic devices and adapted to receive the sensor signals from the second wire and to provide control signals to selected control electronic devices to which the control de-multiplexer is coupled. a first mobile carriage which supports a first scanner head in which the first set of sensor electronic devices is housed wherein, for at least a plurality of the sensor electronic devices, each has a sensor input; a first set of control electronic devices that is located in a module remotely from the first scanner head and which is separated by a distance of at least 50 meters from the first scanner head, wherein for at least a plurality of the control electronic devices, each has a control output; a control multiplexer that is coupled to the plurality of control electronic devices and which is located in the same module containing the first set of control electronic devices and adapted to receive input signals therefrom and to provide control signals of the plurality of control electronics for transmission through a first wire; a sensor de-multiplexer that is coupled to the plurality of sensor electronic devices and adapted to receive the control signals from the first wire and to provide sensor signals to selected sensor electronic devices to which the sensor de-multiplexer is coupled; a ground wire that connects the control multiplexer and the sensor de-multiplexer; means for driving a mobile carriage (28, 30, 32, 34) along the main scanning direction which has a distance of at least six meters; a second set of sensor electronic devices, that is housed in a second scanner head that is supported by a second mobile carriage, wherein for at least a plurality of these sensor electronic devices, each has a sensor output; a second set of control electronic devices, that is located in a module remotely from any scanner head (2,18) and which is separated by a distance of at least 50 meters from any scanner head (2,18), wherein for at least a plurality of these control electronic devices, each has a control input; a sensor multiplexer that is coupled to the plurality of sensor electronic devices of the second set and adapted to receive input signals therefrom and to provide sensor signals of the plurality of sensor electronic devices of the second set for transmission through a second wire; and a control de-multiplexer that is coupled to the plurality of control electronic devices of the second set and which is located in the same module containing the second set of control electronic devices and adapted to receive the sensor signals from the second wire and to provide control signals to selected control electronic devices to which the control de-multiplexer is coupled.