Current Hirschmann stock-portfolio image from our 2026-08-19 resource sequence. Confirm the exact BRS20 configuration in the quotation.

The second small switch can be false economy

A panel design may begin with four copper devices and later grow to a PLC, HMI, drives, remote I/O, vision controller, gateway and service connection. Adding another small switch solves the port shortage but also adds a power feed, inter-switch patch cable, DIN-rail space, configuration point and failure location. The BRS20-8TX/2FX 942170004 concentrates eight local copper ports and two managed optical uplinks in one device, which can simplify topology and fault isolation when the application fits its Fast Ethernet limits.

Verified product identity and interfaces

Published distances are reference conditions, not a substitute for a project link calculation. Actual fiber type, modal bandwidth, connector and splice losses, contamination, aging and design margin must be checked.

Port arithmetic: ten ports, two different jobs

The device has ten network ports in total, but they are not interchangeable. The eight RJ45 ports are intended for copper Fast Ethernet endpoints. The two optical ports are fixed multimode SC interfaces and are commonly assigned to backbone or redundancy paths. A design using both fiber ports for a ring can still retain all eight copper ports for local equipment—one reason this layout is useful in machine cells and distributed control cabinets.

BRS20-4TX/2FX versus BRS20-8TX/2FX

The larger model is not automatically better. Select it when the documented endpoint count and growth plan justify eight copper ports. Oversizing without a topology plan can leave unmanaged spare connections; undersizing can force an avoidable second switch.

Five errors an experienced buyer checks first

1. Reading “2FX” as two SFP slots: this exact unit has fixed multimode SC optics.

2. Assuming any SC fiber is compatible: connector shape does not prove fiber mode, wavelength or optical budget.

3. Assuming Gigabit or PoE: the published network ports are Fast Ethernet and this code does not identify PoE.

4. Ignoring the environment code: confirm standard or extended-temperature requirements and all project approvals.

5. Quoting only BRS20: use the complete code and part number because nearby variants differ materially.

When this model is a strong fit

Typical use cases include a machine or process cell with five to eight copper devices and a multimode fiber connection to the plant backbone; a water, transport or material-handling cabinet using dual optical paths; and brownfield replacement where 100BASE-FX multimode SC infrastructure already exists. Managed VLAN, multicast, redundancy, security and diagnostic functions help teams control and troubleshoot the network, subject to the selected software release and project configuration.

RFQ checklist

• Full code BRS20-1000M2M2-STCY99HHSESXX.X.XX and part 942170004

• Quantity, destination and required delivery date

• Fiber core type, SC interface, route length and calculated/measured loss

• Endpoint count, uplink or ring topology and required spare ports

• Operating temperature, power design, software and approvals

Frequently asked questions

What is Hirschmann 942170004?

It is the BRS20-8TX/2FX, code BRS20-1000M2M2-STCY99HHSESXX.X.XX, a ten-port managed Fast Ethernet switch with eight copper RJ45 ports and two fixed multimode SC fiber ports.

Are the two fiber ports SFP slots?

No. They are fixed 100BASE-FX multimode SC optical interfaces.

Can it serve eight devices while using a fiber ring?

The physical layout provides eight copper ports plus two fiber ports, so both optical ports can be allocated to the ring without consuming an RJ45 port. Confirm the complete topology and redundancy configuration before deployment.

Does it support single-mode fiber?

This exact M2M2 configuration is multimode. Select the appropriate single-mode configuration after confirming the complete optical link.

Hot-selling Hirschmann BOBCAT BRS models

All products below are currently in our hot-selling portfolio. Availability, software revision, approvals and lead time are confirmed per quotation.

Technical note: Product identity and core specifications are based on current Hirschmann information and remain subject to revision. Optical compatibility, link budget, software, certifications, availability and lead time are confirmed per quotation. The image represents our Hirschmann stock portfolio and may not depict the exact configuration. We are an independent supplier; trademarks belong to their owners.