HIRSCHMANN MM20-M4M4T1T1SAHH Media Module
HIRSCHMANN MM20-M4M4T1T1SAHH Media Module
The HIRSCHMANN MM20-M4M4T1T1SAHH is a dual-media, 4-port Fast Ethernet expansion module engineered for Hirschmann’s MICE (Modular Industrial Communication Equipment) switch series, specifically designed to fit MS20 and MS30 modular base units.
Featuring 2 optical multimode ST fiber ports and 2 copper RJ45 ports, this hybrid module provides a balanced connectivity solution for control panels requiring local field device connections along with secure, vibration-resistant fiber optic uplinks.
Product Introduction / Overview
The MM20-M4M4T1T1SAHH plugs directly into the expansion slots of MS20 or MS30 modular switches. Its hybrid design utilizes ST (BFOC) optical connectors—a popular, heavy-duty twist-lock fiber connector favored in manufacturing, power utilities, and legacy industrial sites—paired with standard RJ45 copper ports for local PLC, HMI, or I/O integration.
Module Nomenclature Decoding:
[MM20] : Media Module series for Fast Ethernet MICE switches
[M4] : Port 1 -> Multimode 100BASE-FX ST (BFOC) Fiber Connector
[M4] : Port 2 -> Multimode 100BASE-FX ST (BFOC) Fiber Connector
[T1] : Port 3 -> 10/100BASE-TX RJ45 Copper Port
[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 Parameter List
| Parameter | Specification Details |
| Manufacturer / Line | Hirschmann / MICE (Modular Industrial Communication Equipment) |
| Compatible Base Switch | MS20 and MS30 Modular Base Switches |
| Total Port Count | 4 Ports (2 x Fiber + 2 x Copper) |
| Fiber Interface | 2 x 100BASE-FX Multimode Ports (ST / BFOC Connectors) |
| Copper Interface | 2 x 10/100BASE-TX RJ45 Ports (Auto-negotiation, Auto-MDI/MDI-X) |
| Optical Distance | Up to 5 km ($50/125\,\mu\text{m}$ fiber) / up to 4 km ($62.5/125\,\mu\text{m}$ fiber) |
| Optical Wavelength | 1300 nm |
| Power Supply | Powered directly via host switch backplane connection (~6W) |
| Diagnostics | Front-panel LEDs for link, speed, and activity status per port |
| Enclosure Rating | IP20 industrial housing |
Product Features / Core Advantages
Twist-Lock ST Connectors: The ST (BFOC) bayonet connectors provide exceptional mechanical locking and vibration resistance, preventing accidental cable disconnections in high-vibration manufacturing environments.
Balanced Hybrid Density: Combines two optical fiber links for redundant backbone rings with two copper RJ45 ports for local field device aggregation in a single expansion card slot.
Complete EMI/RFI Immunity: Optical fiber connections eliminate ground loops, noise interference, and potential difference issues between control cabinets.
Hot-Swappable Design: Can be added or replaced in live MS20/MS30 base units without causing downtime for adjacent running modules.
Model Classification
The Hirschmann MICE MM20 system offers various port configurations across ST, SC, RJ45. and SFP interfaces:
| Model | Port Configuration | Environmental / Approval Tier |
| MM20-M4M4T1T1SAHH | 2 x Multimode ST Fiber + 2 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) + Standard Approvals |
| MM20-M4M4T1T1EBH | 2 x Multimode ST Fiber + 2 x RJ45 | Extended Temp ($-40^\circ\text{C}$ to $+70^\circ\text{C}$) + Conformal Coating |
| MM20-M2M2T1T1SAHH | 2 x Multimode SC Fiber + 2 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) + Standard Approvals |
| MM20-M2T1T1T1SAHH | 1 x Multimode SC Fiber + 3 x RJ45 | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) + Standard Approvals |
| MM20-T1T1T1T1SAHH | 4 x RJ45 Copper Ports | Standard Temp ($0^\circ\text{C}$ to $+60^\circ\text{C}$) + Standard Approvals |
Environmental Tolerance Conditions
Operating Temperature Range: $0^\circ\text{C}$ to $+60^\circ\text{C}$ ($32^\circ\text{F}$ to $140^\circ\text{F}$)
Storage / Transport Temperature: $-40^\circ\text{C}$ to $+85^\circ\text{C}$ ($-40^\circ\text{F}$ to $185^\circ\text{F}$)
Relative Humidity: 10% to 95% (non-condensing)
Standards Compliance: cUL508. cUL1604. CE Mark, FCC Part 15 Class A
Installation Method
ESD Safety Prep: Wear a grounded electrostatic discharge (ESD) wrist strap prior to handling the module.
Align Guides: Locate an unpopulated expansion slot on the host MS20 or MS30 basic switch. Align the side guides of the MM20 module with the guide tracks in the switch chassis.
Module Insertion: Push the module steadily into the slot until its rear connector seats completely into the backplane board.
Fastening: Tighten the captive thumb screws on the top and bottom of the module faceplate to ensure proper grounding and mechanical stability.
Cabling Connection:
Plug Cat5e/6 industrial cables into the RJ45 copper ports.
Remove protective rubber dust caps from the ST fiber ports. Push and twist the ST fiber connectors clockwise until they lock securely onto the bayonet posts (ensuring Tx on one end aligns with Rx on the other).
Operating Instructions
LED Link Verification: Check the front-panel status LEDs after powering on. Solid green indicates an active physical link, while flashing green indicates active packet transmission.
Dust Prevention: Always keep protective rubber caps fitted on any unused ST fiber ports to prevent airborne dust from contaminating the internal optical lenses.
Hot-Swapping Routine: To replace a running module, disconnect all fiber and copper cables, loosen the captive screws, and pull the module straight out from the chassis frame.