How are the dSMs and the dSS connected? digitalSTROM Support September 28, 2018 06:12 Updated Follow dSMs and dSS are connected via a 2-wire bus on which the dS485 protocol runs. Related articles Can I use a free NYM cable or control line for the dS 485 bus? Is the dS485 bus a SELV or PELV circuit? What is the maximum cable length for a dS485 bus? Which cable do you recommend according to VDE 0100-444 for the dS485 bus? What is the difference between the different digitalSTROM servers?