SUSI for Linux Links http://www.nmra.org/sites/default/files/standards/sandrp/pdf/ti-9.2.3_susi_05_03.pdf http://www.morop.eu/de/normes/nem660_d.pdf http://normen.railcommunity.de/RCN-121.pdf http://www.d-i-e-t-z.de/7_5.htm http://normen.railcommunity.de/RCN-600.pdf