SwGrd The modular ROTEC software provides the user with an easy-to-use, flexible and powerful tool for data acquisition, analysis, display and output. Signals may be analysed as a function of time, angle or rotational speed. FFT methods are used when converting from the time to the frequency and order domains. The common time base of all channels ensures reliable cross-channel evaluation of signals (e.g. transmission error or torque between two speed channels) and allows for correlation of analogue signals with speed data..