17.4 Transportation Switches

DIN rail switches serve control cabinets with RJ-45 connectors. Railway and outdoor applications demand M12 connectors, IP40/IP67 housings, and certifications for vibration, EMC, and fire protection. The BXS, BXP, and OCTOPUS managed families address these requirements.

BXS (Gigabit Ethernet for Rolling Stock)

The BXS is a cost-effective Gigabit Ethernet switch designed for onboard train networks. TSN on all ports enables deterministic data delivery for passenger information systems, CCTV, and train control.

Specification	BXS30/32 (FE + GE)	BXS40/42 (Full GE)
Ports	4 GE M12 X-coded + 8 FE M12 D-coded	12 GE M12 X-coded
PoE	BXS32/42: PoE/PoE+	BXS42: PoE/PoE+
Housing	IP40 metal, wall mount	IP40 metal, wall mount
Temperature	-40 C to +70 C	-40 C to +70 C
Software	HiOS L2A	HiOS L2A
Security	Wire-speed ACLs, DoS prevention	Same
TSN	All ports	All ports
Certifications	EN 50155, EN 45545, EN 50121-4	Same

BXP (BOBCAT eXtreme Performance)

The BXP delivers 10 GbE speeds and high port counts for future-ready onboard train networks.

Specification	Value
Ports	20 or 28 port variants
Speed	Up to 6 x 10 GbE + GbE ports
PoE++	120 W budget, PoE++ (IEEE 802.3bt)
Bypass	Maintains network continuity during power failure
Software	HiOS L2A or L3A
Connectors	M12 throughout
Certifications	EN 50155
Temperature	-40 C to +70 C

Note

The BXP bypass function keeps the Ethernet path alive when the switch loses power. Traffic passes through the bypass relay without switching or filtering. This prevents a single switch power failure from partitioning the train network.

OCTOPUS Managed

Full managed IP65/67 switches for outdoor and harsh-environment installations. Layer 2 and Layer 3 routing. M12 connectors. Up to 28 ports.

Specification	OS20/24 (FE)	OS30/34 (FE+GE)	OS3-40/44 (Full GE)
Ports	Up to 28 FE	Up to 4 GE + 24 FE	Up to 24 GE
PoE+	Up to 15 ports, 120 W	Up to 24 ports, 120 W	Up to 24 ports, 120 W
Software	HiOS L2S, L2A, L3S	HiOS L2A, L3A	HiOS L2A, L3A
Protection	IP65/67	IP65/67	IP65/67
Temperature	-40 C to +70 C	-40 C to +60/70 C	-40 C to +60/70 C
Certifications	EN 50155, EN 45545, EN 50121-4, DNVGL	Same	Same

M12 Connector Types

Railway and IP67 switches use M12 connectors instead of RJ-45. The coding determines the signal type:

Coding	Signal	Speed	Use
A-coded	Power, serial (V.24)	N/A	Power supply, console
D-coded	Fast Ethernet	100 Mbps	FE data ports
X-coded	Gigabit Ethernet	1 Gbps / 10 Gbps	GE/10GE data ports

Caution

M12 D-coded connectors support Fast Ethernet only (100 Mbps). Gigabit Ethernet requires M12 X-coded connectors. Verify the connector coding before ordering cables.

Railway Standards

Standard	Scope
EN 50155	Electronic equipment for rolling stock: temperature, vibration, humidity, EMC, power supply variations
EN 45545	Fire protection in railway vehicles. HL3 = highest hazard level
EN 50121-4	EMC for railway signaling and trackside equipment
E1	Type approval for road vehicles

Key Takeaways

BXS: cost-effective train switch with TSN

12 ports, M12 connectors, TSN on all ports, PoE+, EN 50155/45545/50121-4. The standard choice for rolling stock.

BXP: 10 GbE with bypass for future-ready trains

Up to 28 ports, 10 GbE, PoE++, bypass function. For high-bandwidth onboard networks.

What Comes Next

Transportation switches serve onboard and trackside networks. The next chapter covers rack mount switches (GREYHOUND and DRAGON MACH) for plant-level distribution and backbone aggregation.

References

• Belden/Hirschmann. (2024). BXS Data Sheet. Belden Inc.
• Belden/Hirschmann. (2024). BXP Data Sheet. Belden Inc.
• Belden/Hirschmann. (2024). OCTOPUS Managed Series Data Sheet. Belden Inc.