A method for filing a retarder with an operating fluid through a valve connected to a fluid reservoir having air pressure Pv and conveying an operating fluid with an actuating pressure Py in the retarder. In one embodiment, a fish processing machine in accordance with the invention includes a fish processing unit for use with a processing machine having a fillet assembly andor a skinner assembly. A swash plate is inclinably and slidably coupled to the driving shaft. For smoke particles, significantly more blue light is scattered than infra-red radiation, but this is not so much the case for non-smoke particles. Also, a fourth channel interface is configured to receive the second data packet stream from the channel connection.