The NCU 720.3B PN represents the medium configuration level of the SINUMERIK 840D sl. Up to 31 axes are available in a maximum of 10 machining channels, which can be executed in up to 10 mode groups. Up to 20 axes/spindles are supported per channel. Interpolation is possible for a maximum of 20 axes with the CNC software for NCU (multi-axis interpolation option).

The basic version of the CNC user memory is 10 MB, and can be optionally expanded up to 22 MB.