My SG300-10 & SG300-20 work perfectly with: StarTech.com MXT100FF Straight Through Serial Cable - DB9 F/F, Gray - F/F, 6 feethttps://www.amazon.co.uk/dp/B00066HP2E/ref=cm_sw_em_r_mt_dp_U_LdRxDb8VJN5N1coupled with:Plugable USB to RS-232 DB9 Serial Ada...