It quite similar to DCC but manufacturer specific. Like MTH to be exact has DCS, but in HO at least they will beswitching over with the second run of the SD70ACe, and other new released HO locos. DCS is not compatable with DCC you and others had to run two seperate systems on their layouts. Thank goodness MTH locos old run or 1st if you will are duel DCC/DCS?DC actually.I just was wondering what DCS was. I assume it is closely related to DCC, so that is why i am posting it here.