The RUGGEDCOM RS401NC is an industrially hardened, serial device server with an integrated, fully managed, Ethernet switch, designed to operate reliably in electrically harsh and climatically demanding environments. 56-bit Encryption; compact design, 4 port serial server, 4 port managed Ethernet switch & an optional V.90 modem 24 = 24 VDC (10-36 VDC), No power module 2 D = Front panel mount with DIN screw points none C01 = Manufacturing modification: Conformal TXTX = 10/100BaseTX RJ45 3D = 4x RS232/RS422/RS485 via DB9 XX = No modem