  A novel magnetic configuration sweep control system for the TJ-II Heliac
device is described. The system is prepared to establish a reference for
plasma, torus or vessel current while the coil configuration currents are swept
during a single plasma discharge. It can also be run in a special simulation
mode, which does not require powering the TJ-II device, intended for
commissioning and experiment preparation purposes. Preliminary tests with the
system have shown its ability to perform rotational transform scans while
establishing a waveform for torus current independently, despite variable
plasma conditions. This opens up new experimental possibilities to study the
influence of rotational transform and shear independently.
