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

Single-mode reaches farther—but distance is not the first calculation

When two industrial areas are separated by a long route, single-mode fiber is often selected before the actual optical path is documented. That is backwards. A reliable design starts with fiber type, transmitter and receiver limits, every connector and splice, route attenuation, aging allowance and reserve. The BRS20-4TX/2FX-SM 942170005 combines four local copper connections with two managed single-mode SC uplinks, but its published maximum distance remains conditional on the complete link budget.

Verified product identity and optical facts

Why “up to 32.5 km” is not a purchasing guarantee

The published distance is derived from stated reference assumptions. A real route may include older fiber, patch panels, dirty connectors, fusion splices, mechanical splices and future maintenance points. A correct design compares the transmitter output range with receiver sensitivity and overload limits, subtracts all path losses, and keeps an engineering margin. Distance alone cannot prove that a link will work.

Where the two single-mode ports add value

Two optical interfaces can form a backbone in/out path, connect two remote locations or support an engineered redundant ring while four RJ45 ports remain available for local equipment. This is useful for remote process skids, water and wastewater stations, transport cabinets, utility sites and brownfield networks where fixed 100BASE-FX single-mode SC infrastructure already exists.

Multimode 942170003 or single-mode 942170005?

These two models look similar in a short description, but the optical interfaces are not interchangeable. Replacing a multimode unit with the SM version—or the reverse—requires checking both ends of every link.

Six procurement traps to avoid

1. Confusing SM with an SFP slot: “SM” means single-mode; this product has fixed optics.

2. Ordering by short name: quote the full S2S2 configuration and 942170005.

3. Checking kilometers but not dB: link loss and receiver limits decide viability.

4. Assuming Gigabit: these ports are Fast Ethernet.

5. Ignoring temperature and approvals: confirm environment code and project certifications.

6. Forgetting the remote end: wavelength, mode, connector, speed and optical power must match.

RFQ information that prevents a wrong quotation

• Full code BRS20-0600S2S2-STCY99HHSESXX.X.XX and part 942170005

• Quantity, destination and required delivery date

• Remote device model and optical interface

• Fiber type, connector, route length, splices and measured/calculated loss

• Topology, temperature, software and required approvals

Frequently asked questions

What is Hirschmann 942170005?

It is the BRS20-4TX/2FX-SM, code BRS20-0600S2S2-STCY99HHSESXX.X.XX, a six-port managed Fast Ethernet switch with four RJ45 ports and two fixed single-mode SC fiber ports.

Are the fiber interfaces replaceable SFP modules?

No. The two 100BASE-FX single-mode SC optical interfaces are fixed.

Will every 32.5 km link work?

No. The official distance is based on stated reference assumptions. The actual fiber route and optical budget must be calculated and verified.

Can it connect directly to a multimode 100BASE-FX port?

Do not assume compatibility. Select matching optical media or use a properly engineered conversion solution after checking both interfaces.

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 Belden/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.