HIRSCHMANN MM20-M2T1T1T1TAHH Media Module
HIRSCHMANN MM20-M2T1T1T1TAHH Media Module
The HIRSCHMANN MM20-M2T1T1T1TAHH is a high-reliability, hybrid 4-port Fast Ethernet expansion module engineered for Hirschmann’s MICE (Modular Industrial Communication Equipment) switch series, including the MS20 and MS30 modular basic units.
Featuring 1 optical multimode SC fiber port and 3 copper RJ45 ports, alongside an extended operating temperature rating, this module bridges localized IP field devices with long-distance fiber networks in demanding industrial environments.
Product Introduction / Overview
The MM20-M2T1T1T1TAHH plugs directly into the expansion slots of MS20 or MS30 basic switch chassis. Its hybrid port layout allows control engineers to connect up to three local field devices (PLCs, HMIs, or I/O blocks) via standard copper Ethernet cables, while utilizing a single noise-immune multimode optical uplink to connect back to a central control cabinet.
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
[T] : Extended Operating Temperature Range (-40°C to +70°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, MS30 Modular Base Units |
| 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 Distance | 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 $+70^\circ\text{C}$ |
| Power Supply | Powered directly 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: 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. Disconnect all network cables prior to loosening the captive screws.
Optical Dust Protection: Keep the protective rubber cap inserted into the SC fiber port whenever no fiber cable is connected to prevent optical lens contamination.
Copper Cable Connection: RJ45 ports automatically adjust line speed (10/100 Mbps) and support automatic crossover (Auto-MDI/MDI-X).
Fault Diagnosis
| LED State / Symptom | Possible Cause | Recommended Action |
| Port Link LED OFF | Cable disconnected or broken | Inspect physical cable connection; verify Tx/Rx fiber polarity is crossed correctly. |
| Fiber Link LED OFF | Dirty optical SC ferrule | Clean the optical fiber end-faces using an isopropyl alcohol cleaning pen. |
| Yellow/Amber Flashing | Data packet traffic / collision | Normal data activity; check duplex mode settings if network latency is high. |
| Module Unresponsive | Poor backplane connection | Loosen screws, unseat and firmly reinsert module into chassis slot, then retighten screws. |
Related Models of the Same Series
| Model | Port Configuration | Environmental / Approval Tier |
| MM20-M2T1T1T1SAHH | 1 x Multimode SC + 3 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-M2T1T1T1TAHH | 1 x Multimode SC + 3 x RJ45 | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) |
| MM20-M2T1T1T1EBH | 1 x Multimode SC + 3 x RJ45 | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
| MM20-M2M2M2M2SAHH | 4 x Multimode SC Fiber | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) |
| MM20-T1T1T1T1SAHH | 4 x RJ45 Copper Ports | 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: Store in original anti-static packaging in a dry, dust-free environment until deployment.