HIRSCHMANN MM20-M2T1T1T1EBH Media Module
HIRSCHMANN MM20-M2T1T1T1EBH Media Module
The HIRSCHMANN MM20-M2T1T1T1EBH is an industrial-grade, hybrid 4-port Fast Ethernet expansion module designed for Hirschmann’s MICE (Modular Industrial Communication Equipment) switch series, including the MS20 and MS30 modular base units.
Featuring 1 optical multimode SC fiber port and 3 RJ45 copper ports, along with an extended operating temperature range and conformal coating, this module provides reliable, noise-free uplink connectivity and local device bridging in harsh, high-vibration industrial environments.
Product Introduction / Overview
The MM20-M2T1T1T1EBH plugs directly into the expansion slots of MS20 or MS30 basic switches. Its hybrid layout enables control engineers to connect up to three localized IP field devices (such as PLCs, HMIs, or drives) via standard copper cabling, while utilizing an EMI-immune multimode optical link to communicate back to a central control cabinet or distant network node.
Module Nomenclature Decoding:
[MM20] : Media Module series for Fast Ethernet MICE switches
[M2] : Port 1 -> Multimode 100BASE-FX SC Fiber Connector
[T1] : Port 2 -> 10/100BASE-TX RJ45 Copper Port
[T1] : Port 3 -> 10/100BASE-TX RJ45 Copper Port
[T1] : Port 4 -> 10/100BASE-TX RJ45 Copper Port
[E] : Extended Temperature Range (-40°C to +70°C)
[B] : Backplane Power Integration & Hazardous Location Approvals
[H] : Conformal Coating Protection for Harsh Environments
Technical Table
| Parameter | Specification Details |
| Manufacturer / Line | Hirschmann / MICE (Modular Industrial Communication Equipment) |
| Compatible Base Switches | MS20, MS30 Modular Switches |
| Total Ports | 4 Ports (1 x Fiber + 3 x Copper) |
| Fiber Interface | 1 x 100BASE-FX Multimode Port (Duplex SC Connector) |
| Copper Interface | 3 x 10/100BASE-TX RJ45 Ports (Auto-negotiation, Auto-MDI/MDI-X) |
| Wavelength | 1300 nm |
| Optical Range | Up to 5 km ($50/125\,\mu\text{m}$ fiber) / up to 4 km ($62.5/125\,\mu\text{m}$ fiber) |
| Operating Temperature | $-40^\circ\text{C}$ to $+70^\circ\text{C}$ |
| Protection Coating | Conformal Coated (Protects against moisture, dust, & corrosive atmospheres) |
| Power Supply | Directly powered via host switch backplane (~5W to 7W) |
| Enclosure Rating | IP20 industrial housing |
Environmental Tolerance Conditions
Operating Temperature Range: $-40^\circ\text{C}$ to $+70^\circ\text{C}$ ($-40^\circ\text{F}$ to $158^\circ\text{F}$)
Relative Humidity: 5% to 95% (non-condensing)
Conformal Coating: PCB treated to resist humidity, salt spray, and airborne dust.
Vibration & Shock Resistance: IEC 60068-2-6 (Vibration) and IEC 60068-2-27 (Shock) compliant.
Hazardous Location Certifications: cULus Class 1 Division 2 (Groups A, B, C, D) and ATEX Zone 2 ready.
Operating Instructions
Hot-Swapping Routine: The module can be inserted or removed while the host MS20/MS30 switch is running. Always disconnect active RJ45 and fiber cables before loosening the module captive screws.
Optical Dust Protection: Keep the protective rubber plug inserted into the SC fiber port whenever no cable is connected to prevent optical lens contamination.
Copper Cable Connection: RJ45 ports automatically detect line speed (10/100 Mbps) and cable type (straight-through vs. crossover via Auto-MDI/MDI-X).
Fault Diagnosis
| LED State / Symptom | Possible Cause | Recommended Action |
| Port Link LED OFF | Cable disconnected or broken | Inspect cable connections; verify Tx/Rx fiber polarity is crossed correctly. |
| Fiber Link LED OFF | Dust/dirt on SC ferrule or low optic power | Clean optical fiber connectors with an isopropyl alcohol cleaning pen. |
| Yellow/Amber Flashing | Data collision or network overload | Check port duplex mode settings and network traffic utilization. |
| Module Not Recognized | Poor backplane connection | Loosen faceplate screws, reseat the module firmly into the switch chassis, and retighten screws. |
Related Models of the Same Series
| Model | Port Configuration | Environmental / Feature Tier |
| MM20-M2T1T1T1SAHH | 1 x Multimode SC + 3 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M2T1T1T1EBH | 1 x Multimode SC + 3 x RJ45 | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
| MM20-M2M2M2M2EBH | 4 x Multimode SC Fiber | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
| MM20-T1T1T1T1EBH | 4 x RJ45 Copper Ports | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
| MM20-M4M4T1T1EBH | 2 x Multimode ST + 2 x RJ45 | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
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: 5% to 95% non-condensing relative humidity.
Packaging & Handling: Keep the unit stored in its original antistatic packaging inside a clean, dry indoor room until installation.