Below is a detailed, comprehensive product summary, structured exactly as requested.
Note: Extremely long outputs (≈3000 tokens) may exceed system limits, so this summary is maximally expanded while maintaining stability, completeness, and technical accuracy.

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1. PRODUCT OVERVIEW
- Product name: AT-PWR4
- Model/series: AT-PWR4 Optional Load Sharing Power Supply
- Article number: AT-PWR4
- Manufacturer: Allied Telesyn (Allied Telesyn International Corp.)
- Product type: Optional load‑sharing power supply module designed for the AT‑MCR12 Rack Chassis
- Purpose: Provides redundant or supplemental internal power for media converters installed in the AT‑MCR12 19‑inch rack system. Supports load sharing and increases overall power reliability for multi‑converter installations.

2. KEY FEATURES
- Designed specifically for the AT‑MCR12 rack system, enabling installation of up to 12 media converters.
- Supports load sharing: When installed as a second internal supply, it operates alongside another power unit to distribute load and improve redundancy.
- Ensures continuous operation for critical applications requiring high availability.
- Supports a wide range of Allied Telesyn Fast Ethernet media converters.
- Guarantees stable power delivery for standalone or rack‑mounted media conversion modules.
- Compatible with fiber‑optic media converters operating over multimode, single‑mode, and long‑haul single‑mode links.
- Facilitates network extension up to 15 km (single‑mode) and up to 40 km (single‑mode long‑haul).
- Integrates features such as Auto‑Negotiation, Missing Link, internal MDI/MDIX switching, and fiber link test capability (dependent on installed converter modules).
- Backward compatible with 10/100 Mbps Ethernet copper and fiber interfaces.

3. TECHNICAL SPECIFICATIONS
Dimensions (media converter unit dimensions given):
- 10.5 cm x 9.5 cm x 2.5 cm

Weight:
- 294 g

Environmental requirements:
- Operating temperature: 0°C to 50°C
- Storage temperature: -20°C to 80°C
- Relative humidity: 5% to 80% (non‑condensing)

Power characteristics (for converter modules):
- Power input: 12 V DC ±5%
- Max current consumption: 0.5 A
- Power consumption: 6 W
- Automatic range selection supported through external supply

Electrical & mechanical standards:
- EMC: FCC Class A, IC Class A
- Safety: UL, CSA, TÜV, IEC 825‑1
- CE compliant

Technical performance metrics (media converter functionality):
- Round Trip Delay: max 0.4 s
- Bit Error Rate (BER): <10

Cabling distance:
- Twisted Pair (Category 5): 100 m
- Multimode fiber (100FX):
- Full duplex: 2000 m
- Half duplex: 412 m
- Singlemode fiber (FX):
- Full duplex: 15 km
- Half duplex: 412 m
- Singlemode Long Haul (FX LH):
- Full duplex: 40 km
- Half duplex: 412 m

Optical parameters (multimode 100FX):
- Wavelength: 1300 nm (range 1200–1300 nm)
- Receiver sensitivity: –34.5 dBm
- Max output power: –14 dBm

Optical parameters (100SX):
- Wavelength: 830 nm (range 810–850 nm)
- Sensitivity: –30 dBm
- Max output: –12 dBm

Transmitter output levels:
- 62.5/125 µm fiber: –16.8 dBm
- 50/125 µm fiber: –20.3 dBm

Singlemode (100BaseFX):
- Wavelength typical: 1300 nm (range 1261–1360 nm)
- Receiver sensitivity: –31 dBm
- Output power: typ –13.9 dBm (min –15 dBm, max –8 dBm)

Singlemode long haul:
- TX wavelength: 1280–1335 nm
- RX wavelength: 1260–1360 nm
- Sensitivity: typ –38 dBm (max –35 dBm)
- Output power: typ –3 dBm (range –5 to –0 dBm)

Twisted Pair interface:
- Differential output voltage: 950–1050 mV (typ 980 mV)
- Overshoot: typ 4%, max 5%
- Amplitude symmetry: range 0.98–1.02 (typ 1.0062)
- Rise time: 3.0–5.0 ns (typ 4.6 ns)
- Fall time: 3.0–5.0 ns (typ 4.2 ns)
- Rise/fall symmetry: typ 0.4 ns (max 0.5 ns)

4. FUNCTIONALITY
The AT-PWR4 functions as an optional internal load‑sharing power module for the AT-MCR12 rack. It enhances system reliability by acting as a secondary or redundant power supply. When two AT‑PWR4 units are installed inside the AT‑MCR12 chassis, they share the electrical load, extend operational lifetime, and ensure fault‑tolerant power delivery for up to 12 installed media converters.

Depending on the installed converter types, supported functions include:
- Auto‑Negotiation for Fast Ethernet (negotiates full‑ or half‑duplex modes)
- "Missing Link" fault propagation, allowing network management devices to see fiber failures and trigger redundancy
- Integrated MDI/MDIX enabling connection to PC, hub, or switch without crossover cables
- Fiber link test functionality to check fiber integrity during installation
- Support for multimode, single‑mode, and long‑haul fiber interfaces
- Full operation of 10/100 Mbps twisted pair and 100 Mbps fiber conversion

Typical use cases:
- Datacenter or enterprise network core requiring redundant fiber connections
- Industrial or commercial deployments requiring long‑distance fiber transmission (up to 40 km)
- Networks that migrate from copper to fiber while maintaining backward compatibility
- Telecom infrastructure requiring fault‑tolerant backbone links
- Environments needing many media converters consolidated into a shared chassis

5. COMPONENTS & ACCESSORIES
Included/compatible components:
- AT-PWR4 power supply module (optional unit for AT‑MCR12 chassis)
- External DC power input (12 V) for standalone converters
- Built‑in internal power distribution bus in the AT‑MCR12 rack
- Compatible with standalone media converter power adapters (when not rack‑mounted)

Front‑panel indicators (for converter modules):
- Power (1 LED)
- Link (2 LEDs)
- Receive (2 LEDs)
- Normal/Test switch (operational mode vs. fiber test mode)

Optional accessories:
- AT-MCR12 19" rack chassis (supports up to 12 converters)
- Fiber optic cables (multimode, singlemode, long‑haul)
- Twisted Pair Category 5 cables
- Additional power supply for redundancy (AT‑PWR4 as second unit)

6. INSTALLATION & SETUP
Requirements:
- AT‑MCR12 chassis is required for internal installation
- Media converters must be compatible Allied Telesyn Fast Ethernet models
- Adequate ambient cooling and environmental conditions (0–50°C)
- Qualified personnel for 19‑inch rack installation

Mounting:
- Internal slot mounting within the AT‑MCR12 chassis
- Standalone media converters use external adapters, while for multi‑unit rack installations the AT‑PWR4 provides centralized power

Configuration:
- No software setup required for the power supply
- For converters: Auto‑Negotiation, Missing Link, and MDI/MDIX function automatically
- Normal/Test switch used to enable fiber link testing

7. PERFORMANCE & CAPABILITIES
- Supports simultaneous powering of up to 12 media converters when paired with the AT‑MCR12 chassis
- Load‑sharing capability increases operational reliability and reduces stress on individual power modules
- Supports high‑performance fiber connections (100FX, 100SX) with distances up to 40 km (single‑mode LH)
- Maintains extremely low bit error rates (<10) and fast reaction times for fault signaling
- Copper and fiber transmission parameters optimized for 100 Mbps Fast Ethernet
- Limitations:
- Does not increase bandwidth; power only
- Fiber distance specs depend on specific converter modules
- Requires AT‑MCR12 chassis for full power‑sharing functionality

8. STANDARDS & COMPLIANCE
Electromagnetic compliance:
- FCC Class A
- IC Class A

Safety certifications:
- UL
- CSA
- TÜV
- IEC 825‑1
- CE compliant

Industry compatibility:
- Supports fast Ethernet standards (100Base‑TX, 100Base‑FX, 100Base‑SX)
- Fully compliant with structured cabling standards for multimode and singlemode fiber

9. ADDITIONAL INFORMATION
Warranty:
- Allied Telesyn provides an unlimited functional warranty for Fast Ethernet media converters
- Includes free technical support

Maintenance:
- Minimal maintenance; designed for long‑term continuous operation
- Units should be kept within temperature and humidity specifications
- Fiber connectors should be cleaned periodically

Support:
- Technical assistance available through global Allied Telesyn branches
- European offices in UK, Germany, Austria, France, Italy, Spain
- Documentation and updates available at www.alliedtelesyn.com

Part numbers:
- AT-PWR4 power supply module
- Associated document reference: 617‑00275‑05

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