The Hirschmann Rail Data Diode LV Train, model RDD20, is a hardware-enforced unidirectional data security gateway built for railway rolling stock and infrastructure applications that must prevent any possibility of data flowing from a less-trusted network segment back into a more-trusted one. The device consists of two independent routers — DATA IN and DATA OUT — connected by a physically unidirectional 100 Mbit/s data path within the housing, making reverse communication fundamentally impossible regardless of software configuration or attack vectors. This makes the Rail Data Diode LV Train particularly relevant for protecting operational technology networks, train control systems, or sensitive onboard data sources from cyber threats originating on passenger Wi-Fi or external-facing network segments. The port configuration provides 14 ports in total — 6 x M12 D-coded ports and 8 x RJ45 ports — alongside V.24 serial interfaces via RJ11 sockets and dual SD card slots for ACA31 AutoConfiguration Adapter support. Power is supplied at 2 x 24 VDC (16.8 to 32 VDC) with a total consumption of 23W. The device runs HiOS 09.0.09 software and supports an extensive Layer 2 switching feature set including VLAN (802.1Q), protocol-based VLAN, QoS, IGMP Snooping, HIPER-Ring, MRP (IEC 62439-2), LACP, Sub Ring Manager, RSTP, and VRRP with HiVRRP enhancements. Layer 3 routing capabilities cover OSPFv2, RIP v1/v2, VLAN-based routing interfaces, and static unicast routing. Security features include 802.1X, DHCP Snooping, Dynamic ARP Inspection, RADIUS, LDAP, VLAN-based ACLs, and audit trail. The DIN rail-mounted IP20 housing operates at -40°C to +70°C and holds CE, EN 50155, EN 45545-2, and EN 50121-4 transport approvals with a 60-month guarantee. Available from Recab, your Nordic partner for Hirschmann railway security solutions.
