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

One switch at the copper–fiber boundary

Many machine networks are copper inside the cabinet but need fiber between production areas. A common emergency fix is to add external media converters to a copper-only switch. That creates extra power supplies, patch leads, mounting points and failure locations. The BRS20-4TX/2FX 942170003 integrates four local copper connections and two managed multimode fiber uplinks in one platform, making it a focused option for a small cell that must join a fiber backbone or redundant ring.

Verified identity and interface facts

The four compatibility questions to answer before ordering

1. Multimode or single-mode? The two fixed optical ports on this exact configuration are multimode. For single-mode fiber, select the appropriate SM configuration rather than relying on an adapter.

2. SC or LC? These are fixed SC interfaces, not LC sockets. Check the installed patch-panel and connector type.

3. Fixed optics or SFP slots? “2FX” here means built-in 100BASE-FX optics. It does not mean two interchangeable SFP cages.

4. What is the optical budget? Verify fiber type, wavelength, total attenuation, connector/splice losses and engineering margin. Connector shape alone does not prove link compatibility.

Why two fiber uplinks matter

Two optical interfaces can support a backbone in/out path or an engineered redundant topology while the four RJ45 ports serve local devices such as a PLC, HMI, drive or remote I/O. The exact design still determines usable endpoint capacity: both optical ports may be committed to a ring, while one or more copper ports may be needed for engineering access or another local switch.

BRS20-4TX/2FX versus nearby variants

A model from the same BOBCAT family can have a materially different optical medium, connector, environmental range or port implementation. Always quote the complete configuration code and part number, not only “BRS20.”

Procurement and commissioning checklist

• Confirm 942170003 and the full code on the quotation and packing documents.

• Record fiber core type, connector type, route length and measured or calculated loss.

• Confirm the network topology, redundancy protocol and which ports are reserved for uplinks.

• Check operating temperature, cabinet protection, power design and project approvals.

• Align the required HiOS/software revision, configuration backup and spare-unit plan.

Frequently asked questions

What is Hirschmann 942170003?

It is the Hirschmann BRS20-4TX/2FX, full code BRS20-0600M2M2-STCY99HHSESXX.X.XX, a managed six-port Fast Ethernet switch with four copper RJ45 ports and two fixed multimode SC fiber ports.

Does BRS20-4TX/2FX use SFP transceivers?

No. The two 100BASE-FX multimode SC optical interfaces are fixed. Choose a separate SFP-slot configuration when field-replaceable optical modules are required.

Can it connect to single-mode fiber?

Not as the intended optical medium for this exact M2M2 configuration. Specify the matching single-mode model or another engineered solution after checking the complete link.

What information should an RFQ include?

Send the full code, part number, quantity, destination, required delivery date, fiber type, connector, distance/loss, topology, environmental range and approvals.

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.