HIRSCHMANN MM20-M4M2M2T1SAHH Media Module
HIRSCHMANN MM20-M4M2M2T1SAHH Media Module
The HIRSCHMANN MM20-M4M2M2T1SAHH is a highly flexible, multi-interface 4-port Fast Ethernet media module designed for Hirschmann’s MICE (Modular Industrial Communication Equipment) series switches, specifically fitting MS20 and MS30 modular base chassis.
Featuring a specialized combination of 1 ST multimode fiber port, 2 SC multimode fiber ports, and 1 RJ45 copper port, this multi-media expansion module serves as an ideal bridge for mixing different optical connector standards while maintaining local field device access.
Product Introduction / Overview
The MM20-M4M2M2T1SAHH plugs directly into the backplane expansion slots of MS20 or MS30 modular switches. Its unique triple-interface port arrangement allows industrial automation engineers to interconnect legacy ST (BFOC) twist-lock fiber cables and modern SC duplex fiber runs within a single switch node without requiring external media converters, while leaving one copper RJ45 port for local PLC or HMI diagnostics.
Module Nomenclature Decoding:
[MM20] : Media Module series for Fast Ethernet MICE switches
[M4] : Port 1 -> Multimode 100BASE-FX ST (BFOC) Fiber Connector
[M2] : Port 2 -> Multimode 100BASE-FX SC Fiber Connector
[M2] : Port 3 -> Multimode 100BASE-FX SC Fiber Connector
[T1] : Port 4 -> 10/100BASE-TX RJ45 Copper Port
[S] : Standard Operating Temperature Range (0°C to +60°C)
[A] : Standard Industrial Approvals (cUL508. CE, FCC)
[HH] : Dual Hirschmann Standard Release / Firmware Compliance
Technical Table
| Parameter | Specification Details |
| Manufacturer / Line | Hirschmann / MICE (Modular Industrial Communication Equipment) |
| Compatible Base Switches | MS20 and MS30 Modular Base Units |
| Total Ports | 4 Ports (3 x Fiber + 1 x Copper) |
| Fiber Interfaces | 1 x 100BASE-FX ST Multimode + 2 x 100BASE-FX SC Multimode |
| Copper Interface | 1 x 10/100BASE-TX RJ45 Port (Auto-negotiation, Auto-MDI/MDI-X) |
| Wavelength | 1300 nm |
| Optical Distance | Up to 5 km ($50/125\,\mu\text{m}$ fiber) / up to 4 km ($62.5/125\,\mu\text{m}$ fiber) |
| Operating Temperature | $0^\circ\text{C}$ to $+60^\circ\text{C}$ |
| Power Supply | Powered directly via host switch backplane (~6W) |
| Enclosure Rating | IP20 industrial housing |
Environmental Tolerance Conditions
Operating Temperature Range: $0^\circ\text{C}$ to $+60^\circ\text{C}$ ($32^\circ\text{F}$ to $140^\circ\text{F}$)
Relative Humidity: 10% to 95% (non-condensing)
Vibration & Shock Resistance: IEC 60068-2-6 (Vibration) and IEC 60068-2-27 (Shock) compliant
Industrial Safety Standards: cUL508. cUL1604. CE Mark, FCC Part 15 Class A
Operating Instructions
Hot-Swapping Routine: The module can be inserted or removed while the host MS20/MS30 switch is powered on. Always disconnect active fiber and copper cables before loosening the captive screws.
Optical Dust Protection: Keep protective rubber plugs inserted into any unused ST or SC fiber ports to prevent airborne dust contamination on internal lenses.
Cable Insertion:
ST Port (Port 1): Push the bayonet connector onto the port post and twist clockwise to lock.
SC Ports (Ports 2 & 3): Push the duplex SC connector straight into the port until it clicks firmly into place.
RJ45 Port (Port 4): Standard Cat5e/6 connection with automatic speed and crossover detection.
Fault Diagnosis
| LED State / Symptom | Possible Cause | Recommended Action |
| Port Link LED OFF | Cable disconnected or broken | Inspect cable integrity; verify Tx/Rx fiber polarity is crossed properly on fiber connections. |
| Fiber Link Error | Dirty optical ferrule | Clean the fiber connector end-faces using a $2.5\,\text{mm}$ optical cleaning pen or alcohol swab. |
| Yellow/Amber Flashing | Data traffic activity / collision | Normal data transmission; if performance degrades, verify duplex match settings. |
| Module Unresponsive | Backplane connector improperly seated | Loosen screws, unseat and firmly reinsert the module into the switch slot, then retighten screws. |
Related Models of the Same Series
| Model | Port Configuration | Environmental / Approval Tier |
| MM20-M4M2M2T1SAHH | 1 x ST Fiber + 2 x SC Fiber + 1 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M4T1M2T1SAHH | 1 x ST Fiber + 1 x SC Fiber + 2 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M4M4T1T1SAHH | 2 x ST Fiber + 2 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M2M2T1T1SAHH | 2 x SC Fiber + 2 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M2T1T1T1SAHH | 1 x SC Fiber + 3 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
Storage Conditions
Storage Temperature Range: $-40^\circ\text{C}$ to $+85^\circ\text{C}$ ($-40^\circ\text{F}$ to $185^\circ\text{F}$)
Storage Humidity: 10% to 95% non-condensing relative humidity
Packaging & Handling: Keep the module stored in its original anti-static bag in a clean, dust-free indoor location until final deployment.