Mitsubishi Electric PLC CPU unit - Mitsubishi Electric (MELSEC-Q QnU series) - 10Ksteps / 40KBytes (Program) memory capacity - connection capacity 1024 x I/O points - with USB connector + 9-pin D-Sub female connector (RS-232) - with RS-232 communication capability - Supply voltage 5Vdc (from dedicated Q-series P.S.U.) - Backplane / rack mounting