An incremental rotary encoder that is already connected to an electrical machine and analyzed by a frequency inverter must now be read and analyzed by an HBM Genesis HighSpeed series data recorder as well. Due to the unknown input impedance of the inverter and the unknown potential difference, analysis electronics with electrical isolation will be required between the data recorder and the incremental rotary encoder. This report describes a circuit for optical separation of the encoder signal, with an introduction to parameterization of Perception software for position analysis. The tracks of incremental rotary encoder HOG75 are recorded with the HBM GEN3i data recorder and the Perception software. The result is then used to determine the current angle of rotation of the motor. This encoder has a resolution of 1024 increments per revolution. The three tracks of the encoder are tapped in parallel to the input of the frequency inverter and read on the GEN2i or the successor model GEN3i via the Digital Event/Timer/Counter connector.