I took the db25 pin end apart and checked it out, it has a circuit board that is connected to the db25 connector. only 4 of the 25 pins are being used pins 1 and 3 are the 24volt power supply to the little board, they go to a 8L05A chip which is a 5 volt regulator ic. this powers the board i suspect. pin 9 which is the psc and pin 11 which is the nsc connection go to a SP491EEN RS485 transceiver chip. the db9 side of the cable has 4 wires that are wired for a standard rs232 computer port they in turn go to the little board and from there make it to the transceiver. Im looking into making a cable that uses a converter, there are quite a few on the internet, they now have port powered converters, so maybe i could eliminate the 24 volt power supply to the db25 end and just connect the converter from 232port to the psc,nsc multi drop circuit. Im not sure if a port powered converter will work. also not sure why dover used the 24 volt power supply to power up the board, maybe they had no port powered converters at the time? I received info that the original orange cable is very expensive, 900 dollars. as i did not buy mine, i am not sure if this is correct. any one want to pitch in on this subject. if they are that expensive, then i will continue to pursue making a cheaper one. the converters on the internet are less then 100 bucks..