HIRSCHMANN MM20-P9P9M2T1SAHH Fast Ethernet media module

The HIRSCHMANN MM20-P9P9M2T1SAHH is a hot-swappable, 4-port hybrid Fast Ethernet media module designed for Hirschmann’s modular MICE (Modular Industrial Communication Equipment) switch family, including the MS20 and MS30 basic switch chassis.

What makes the P9P9M2T1 configuration unique is its multi-tier media aggregation layout on a single module backplane slot:

2 × Single-Mode SC Fiber Ports (P9. P9): $100\text{Base-FX}$ duplex SC optical interfaces ($1300\text{ nm}$) capable of long-haul fiber uplinks up to $30\text{ km}$.

1 × Multi-Mode SC Fiber Port (M2): $100\text{Base-FX}$ duplex SC optical interface ($1300\text{ nm}$) for short-to-medium range fiber links up to $5\text{ km}$.

1 × Shielded RJ45 Copper Port (T1): $10/100\text{Base-TX}$ copper port with Auto-Negotiation and Auto-MDI/MDI-X support for direct local device connectivity.

By housing three distinct media types—long-range single-mode optical, short-range multi-mode optical, and copper—in one module, it eliminates the need for external media converters or multi-slot expansions.

2. Product Advantages and Features

3-in-1 Media Flexibility: Bridges long-distance backbone rings, local building/plant multi-mode fibers, and legacy copper field drop connections simultaneously.

Hot-Swappable Backplane Architecture: Plugs directly into the MS20/MS30 backplane under full power without interrupting active network traffic on adjacent slots.

Industrial Hardening & EMI Immunity: Built to withstand severe electromagnetic interference (EMI), high mechanical shock, and continuous vibration in substation and factory automation environments.

Low Power Consumption: Draws power directly from the main switch unit ($\approx 5\text{ W} – 7\text{ W}$), reducing heat dissipation in control cabinets.

Integrated LED Diagnostics: Per-port diagnostic LEDs provide real-time status visibility for power, link state, traffic activity, and transmission speed.

3. Application Cases

A. Substation & Power Grid Automation

Connects remote substations over dual long-haul single-mode lines ($30\text{ km}$ via P9 ports), links local sub-station IEDs (Intelligent Electronic Devices) over multi-mode optical lines (M2 port) for noise isolation, and services an HMI or maintenance PC locally (T1 port).

B. Railway Tracksides & Highway Infrastructure

Used in daisy-chain or redundant ring topologies along transport corridors. The dual P9 ports maintain long-distance ring redundancy between trackside cabinets, while the M2 port links to nearby multi-mode tunnel control units and the T1 port connects directly to IP cameras or sensors.

C. Large Manufacturing Plants

Acts as a media converter hub inside factory floor control panels, aggregating long-run plant backbone cables with legacy multi-mode fiber drops in adjacent workshop bays.

4. Other Models in the Same Series

5. Installation and Maintenance

Installation Steps

ESD Safety: Wear an anti-static wrist strap attached to cabinet ground prior to unpacking or inserting the module.

Backplane Insertion: Align the module with the internal guide rails of an unpopulated slot on the host MS20 or MS30 chassis. Push until the backplane connector locks into place.

Mechanical Fastening: Hand-tighten top and bottom captive thumbscrews on the module faceplate to secure the module and establish ground continuity.

Cabling:

Insert $9/125\,\mu\text{m}$ single-mode fiber jumpers into Ports 1 and 2 (P9. P9).

Insert $50/125\,\mu\text{m}$ or $62.5/125\,\mu\text{m}$ multi-mode fiber jumpers into Port 3 (M2).

Insert Cat5e/Cat6 STP cable into Port 4 (T1).

Maintenance Guidelines

Optical Dust Caps: Keep rubber protective caps inside unpopulated SC receptacles to protect sensitive internal laser optics from airborne dust and oil.

Live Maintenance: The module can be safely extracted or replaced without shutting down power to the host switch frame.

Cleaning: Clean optical fiber connector end-faces with alcohol-free optical lint-free wipes or optical cleaning pens if optical loss increases.