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1. Product Overview
The AT‑MCR12 is a 12‑slot rackmount chassis designed for housing and powering multiple Allied Telesyn media converters. It supports up to twelve standalone Fast Ethernet media converters in a consolidated 19‑inch rackmount form factor. The product name and article designation are both AT‑MCR12. It belongs to the Allied Telesyn media converter and network extension hardware family, used primarily for copper‑to‑fiber conversion and fiber‑based network expansion. The manufacturer is Allied Telesyn International Corp. (later Allied Telesis). The chassis is intended for environments requiring centralized power, organized media conversion deployment, redundant power capability, and scalable copper‑fiber network integration. The chassis consolidates media converter modules that individually allow users to extend Twisted Pair networks over multi‑mode or single‑mode fiber to distances of up to 15 km or 40 km, depending on model.

2. Key Features
• Holds up to 12 standalone media converters in a single 19‑inch rackmount chassis
• Centralized power distribution using one internal power supply, with an option to install a second internal PSU for load sharing and redundancy
• Compatible with Allied Telesyn Fast Ethernet media converters that support Twisted Pair interfaces and multi‑mode, single‑mode, or long‑haul single‑mode optical interfaces
• Scalable copper‑to‑fiber conversion for Ethernet/Fast‑Ethernet networks, supporting distances of 100 m on Category 5 copper, 2,000 m on multi‑mode fiber, 15 km on single‑mode fiber, and 40 km on long‑haul single‑mode fiber
• Fully supports Auto‑Negotiation for Fast Ethernet duplex modes, enabling automatic selection of full or half duplex to maximize bandwidth
• Includes “Missing Link” functionality to ensure accurate link state reporting and support for redundant network topologies
• Provides MDI/MDIX automatic crossover switching for Twisted Pair ports, enabling direct connection to PCs, hubs, or switches with standard TP cables
• Supports integrated fiber link testing to validate fiber integrity without external measurement equipment
• Indicators on front panel include Power, Link, Receive, and Normal/Test mode for operational status feedback
• Designed for easy installation, serviceability, and long‑term operational stability
• Backed by an unlimited lifetime functional warranty and free technical support

3. Technical Specifications
Dimensions of each media converter module: 10.5 cm × 9.5 cm × 2.5 cm
Weight per converter module: 294 g
Environmental ratings:
• Operating temperature: 0 °C to 50 °C
• Storage temperature: –20 °C to 80 °C
• Relative humidity: 5% to 80%, non‑condensing

Electrical and mechanical certifications:
• EMC: FCC Class A, IC Class A
• Safety: UL, CSA, TÜV, IEC 825‑1
• Conforms to CE requirements

Electrical performance:
• Power input: 12 V DC ±5% (supplied by external PSU for standalone units; rackmount chassis uses internal PSU)
• Maximum power consumption: 6 W per converter
• Power draw: 0.5 A max

Front panel indicators for media converter modules:
• Power (converter power status)
• Link (two indicators showing valid receive link)
• Receive (two indicators showing valid incoming data)
• Normal/Test (operating mode or fiber test mode)

Packet transmission metrics:
• Round trip delay: maximum 0.4 seconds
• Bit Error Rate (BER): <10⁻? (value truncated in source; likely <10⁻9 or similar, but preserved as in provided content)

Copper (Twisted Pair) electrical parameters:
• Differential output voltage: typical 980 mV (min 950 mV, max 1050 mV)
• Overshoot voltage: typical 4% (max 5%)
• Single amplitude symmetry: typical 1.0062 (range 0.98–1.02)
• Rise time: typical 4.6 ns (range 3.0–5.0 ns)
• Fall time: typical 4.2 ns (range 3.0–5.0 ns)
• Rise/fall symmetry: typical 0.4 ns (max 0.5 ns)

Fiber interface specifications:

Multimode 100FX:
• Wavelength: 1300 nm typical, range 1200–1300 nm
• Receiver sensitivity: –34.5 dBm
• Maximum optical output power: –14 dBm

Multimode 100SX:
• Wavelength: 830 nm typical, range 810–850 nm
• Receiver sensitivity: –30 dBm
• Maximum optical output: –12 dBm
Transmitter optical output levels for different multimode fiber types:
• 62.5/125 µm: –16.8 dBm
• 100/140 µm and 50/125 µm: –20.3 dBm
• 85/125 µm: (value provided but incomplete; preserved as part of original detail set)

Single‑mode 100BaseFX:
• Wavelength: 1300 nm typical, range 1261–1360 nm
• Receiver sensitivity: –31 dBm
• Optical output power range: typical –13.9 dBm (min –15 dBm, max –8 dBm)

Single‑mode Long Haul:
• Wavelength: 1280–1335 nm (TX), 1260–1360 nm (RX)
• Receiver sensitivity: typical –38 dBm (max –35 dBm)
• Optical output power: typical –3 dBm (range –5 to –0 dBm)

Max cable distances:
• TP Cat 5: 100 m
• Multimode fiber: 2000 m (full duplex), 412 m (half duplex)
• Single‑mode fiber: 15 km (full duplex), 412 m (half duplex)
• Long‑haul single‑mode: 40 km (full duplex), 412 m (half duplex)

4. Functionality
The AT‑MCR12 serves as a centralized chassis for housing multiple Allied Telesyn standalone media converters. The converters themselves perform Ethernet media conversion between Twisted Pair copper interfaces and fiber optic interfaces, supporting multi‑mode, single‑mode, and long‑haul single‑mode fiber. When equipped with converters, the chassis enables large‑scale copper‑to‑fiber transitions within a data center, telecom room, ISP environment, or enterprise network distribution layer.

The Auto‑Negotiation feature allows each converter to automatically configure itself for full‑duplex or half‑duplex Fast Ethernet link modes based on the connected switch or network device. "Missing Link" technology propagates link failures across interconnected interfaces, enabling network management systems to detect fiber link faults and allowing redundant connections to switch over immediately.

The built‑in MDI/MDIX switch on each Twisted Pair port eliminates the need for crossover cables, providing automatic cable‑type detection when connecting to PCs, hubs, or switches. Integrated fiber link testing allows installers to validate the optical path without specialized tools.

Use cases include:
• Extending Ethernet networks over fiber in campus environments
• Connecting remote building switches to a central network core
• Providing long‑distance point‑to‑point or backbone connectivity
• Integrating fiber links into otherwise copper‑based network infrastructures
• Supporting redundant network designs requiring accurate link state signaling
• Centralizing power and management for up to 12 media converters

5. Components and Accessories
Included components (per converter module):
• Media converter unit
• External power supply (for standalone operation)
• TP and fiber interface connectors specific to the installed converter model
• Standard LED status indicators

Rackmount chassis (AT‑MCR12) includes:
• 12 slot mounting bays for converter modules
• One internal power supply (expandable to two for redundancy)
• Power distribution backplane
• 19‑inch rackmount frame compatible with standard telecom racks

Optional accessories:
• Second internal power supply for load sharing/failover
• Fiber patch cables (multimode or single‑mode)
• TP Cat 5/5e/6 cables
• Compatible Allied Telesyn Fast Ethernet media converter models
• Rackmount installation brackets, screws, and cage nuts

6. Installation and Setup
Requirements for rack chassis installation:
• Standard 19‑inch equipment rack or cabinet
• Adequate ventilation to maintain operating temperature of 0 °C to 50 °C
• Ambient humidity between 5% and 80%, non‑condensing
• Stable AC supply powering the chassis internal PSU

Setup steps:
• Mount the AT‑MCR12 chassis in a 19‑inch rack
• Install one or up to twelve media converter modules into the front slots
• Optionally install a second internal power supply
• Connect fiber cables to the fiber ports; ensure correct multimode or single‑mode type
• Connect copper Ethernet devices using standard TP cables; MDI/MDIX eliminates special cabling
• Verify LED indicators for Power, Link, Receive, and Normal/Test
• Run fiber integrity tests using the converter's built‑in link test functionality
• Integrate with switches or network management systems supporting Fast Ethernet Auto‑Negotiation

7. Performance and Capabilities
The chassis itself is a passive housing with integrated power distribution, while the media converter modules provide the active Ethernet conversion performance. Capabilities include:
• Full support for 100 Mbps Fast Ethernet media conversion
• Operation over various fiber types, ranging from short‑range multimode to long‑haul single‑mode
• Transmission distances up to 40 km
• Low BER (<10?? as stated) ensuring reliable optical signal quality
• Internal power redundancy when two PSUs are installed
• Efficient space utilization by consolidating up to 12 converters in a single rack unit
• Power consumption of approximately 6 W per converter, allowing dense deployments
• Support for both half‑duplex and full‑duplex Ethernet

Limitations include:
• Not designed for Gigabit Ethernet or higher‑speed networking
• Half‑duplex distances are limited to 412 m
• Requires appropriate optical fiber type matching to avoid attenuation mismatch
• Maximum per‑converter power draw limits extremely high‑power modules

8. Standards and Compliance
Industry, safety, and EMC standards supported:
• FCC Class A electromagnetic compliance
• Industry Canada IC Class A
• UL safety certification
• CSA certification
• TÜV certification
• IEC 825‑1 (optical safety standard)
• CE conformity for European deployment

Network and interface standards:
• IEEE 802.3 Ethernet
• IEEE 802.3u Fast Ethernet 100Base‑TX, 100Base‑FX, and long‑haul variants
• Auto‑Negotiation compliance for duplex mode configuration
• MDI/MDIX auto‑crossover support
• Optical interface compliance for multimode and single‑mode fiber wavelengths

9. Additional Information
Warranty and support:
• Allied Telesyn provides an unlimited lifetime functional warranty for all Fast Ethernet media converters
• Free technical support ensures easy installation and ongoing maintenance
• Long‑term serviceability backed by a global network of Allied Telesyn offices in the UK, Germany (North & South), Austria, France, Italy, Spain, and others

Maintenance notes:
• Fiber connectors should be cleaned periodically to prevent signal degradation
• Power supply redundancy is recommended for mission‑critical environments
• Firmware updates (if applicable to specific converter models) should be applied as recommended
• Periodic link testing can verify optical performance over time

Reference documentation identifier: 617‑00275‑05
Official manufacturer website: www.alliedtelesyn.com

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