Hirschmann OZD 485 G12-1300 PRO Fieldbus Repeater
Hirschmann OZD 485 G12-1300 PRO Fieldbus Repeater
The Hirschmann OZD 485 G12-1300 PRO (Belden Part Number: 943 892-321) is a high-performance, industrial-grade fiber optic repeater designed to convert electrical RS-485 fieldbus signals into optical signals.
Operating at a long-range 1300 nm wavelength, this device is the industry standard for extending the distance of Modbus, Profibus, or proprietary RS-485 networks over single-mode and multi-mode optical fiber backbones
Product Introduction / Overview
In massive industrial settings such as oil and gas pipelines, sprawling wastewater facilities, and power generation plants, copper-based RS-485 networks are plagued by physical distance limitations and high potential for electromagnetic interference (EMI).
The OZD 485 G12-1300 PRO acts as an active, protocol-transparent repeater that solves these issues.
Featuring 1 electrical RS-485 interface (via a secure screw terminal block) and 2 optical channels (BFOC/ST ports) operating at 1300 nm, this converter enables the integration of fieldbus equipment into highly reliable optical topologies.
The 1300 nm wavelength dramatically reduces signal attenuation over long runs, making it possible to transmit critical data over miles of fiber without needing intermediary repeaters.
Technical Parameter List
| Specification / Parameter | Details |
| Model Code | OZD 485 G12-1300 PRO |
| Belden Order Code | 943 892-321 |
| Supported Protocols | RS-485 fieldbus systems (including Modbus RTU, Modnet, Profibus, etc.) |
| Electrical Interface (Port 1) | 8-pin screw terminal block |
| Optical Interfaces | 2 x Optical Channels (Port 2 and Port 3) utilizing BFOC/ST 2.5 bayonet connectors |
| Optical Wavelength | 1300 nm (low attenuation) |
| Fiber Core Compatibility | Single-mode fiber ($9/125\ \mu\text{m}$) or Multi-mode fiber ($50/125\ \mu\text{m}$ / $62.5/125\ \mu\text{m}$) |
| Maximum Optical Reach | Up to 22 km over Single-mode; up to 5 km over Multi-mode |
| Transmission Rate | 9.6 kbit/s up to 1.5 Mbit/s (automatic baud rate detection) |
| Operating Voltage | Dual redundant inputs: $24\text{ V DC}$ nominal ($18\text{ V}$ to $32\text{ V DC}$) |
| Diagnostic Outputs | 1 x Signaling contact (dry relay, max. 1 A @ 24 V DC); Analog signal strength measurement sockets |
| Dimensions (W x H x D) | $40\text{ mm} \times 156\text{ mm} \times 115\text{ mm}$ (Compact DIN-rail design) |
| Weight | Approximately 500 g |
Product Features / Core Advantages
Ultra-Long Distance Transmission: By utilizing a 1300 nm optical wavelength, this unit can transmit data across single-mode fiber links up to 22 kilometers (13.6 miles) without signal degradation.
Redundant Ring Capability: With 2 independent optical channels, you can construct fully redundant optical fiber rings. If any fiber segment is cut, the OZD 485 PRO reroutes data in under 20 ms to prevent communication downtime.
Universal RS-485 Compatibility: The repeater operates transparently. It automatically adapts to the network’s baud rate (up to 1.5 Mbps) without needing software configuration, making it compatible with almost any RS-485 protocol.
Real-Time Link Quality Diagnostics: Built-in analog measurement sockets on the front panel allow engineers to check optical fiber link quality with a standard voltmeter, catching line deterioration before a failure occurs.
Model Classification
The OZD 485 series structure indicates the following configuration:
OZD 485 – G12 – 1300 PRO
| | | |
[1] [2] [3] [4]
[1] OZD 485: Fiber optic repeater designed for general RS-485 applications.
[2] G12: Glass fiber model featuring 1 electrical RS-485 port and 2 optical channels.
[3] 1300: Emits at a 1300 nm wavelength for long-distance single-mode or multi-mode infrastructure. (Standard models use 850 nm).
[4] PRO: Professional-tier software and physical build, including optical ring redundancy, signaling contacts, and diagnostic ports.
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 Temperature Range: $-40^\circ\text{C}$ to $+70^\circ\text{C}$
Relative Humidity: 10% to 95% (completely non-condensing)
Ingress Protection Rating: IP20 (housed in a rugged, passive-cooling metal enclosure)
Approvals: CE, FCC, cUL508 (safety certification for industrial control equipment)
Installation Method
OZD 485 G12-1300
[DIN Rail Upper Groove]
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\/
====|==== <– Hook upper slot onto standard 35mm rail
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[ OZD ]
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====|==== <– Press bottom home until the spring clip locks
Mounting: Hook the upper mounting slot of the metal DIN-rail clip on the back of the OZD 485 housing over the top edge of a standard 35 mm DIN rail.
Snapping Secure: Press the lower front part of the unit firmly toward the rail until the bottom spring latch snaps into place on the bottom of the rail.
Chassis Grounding: Connect the dedicated grounding terminal screw at the bottom of the housing to your control cabinet’s primary functional ground bus using a low-resistance copper conductor.
Operating Instructions
1. Wiring the RS-485 Electrical Interface (Port 1)
Wire your RS-485 differential lines to the 8-pin screw terminal block according to the pinout configuration on the unit’s side label:
Terminal 1: Data A (-)
Terminal 2: Data B (+)
Terminal 3 & 4 (DGND): Signal reference ground (optional, but highly recommended for long copper segments).
Note: Ensure you terminate the physical end-of-line RS-485 devices with a standard $120\ \Omega$ terminating resistor.
2. Redundancy & Topology Configuration
Before powering on, adjust the front-panel 4-pole sliding DIP switches to define your system design:
DIP Switch 1 & 2 (Operating Mode): Set to specify whether the unit acts as a standalone Line/Star End-Point or as a member of a Redundant Optical Ring.
DIP Switch 3 & 4 (Line Monitoring): Enable or disable the diagnostic alarms for Ports 2 and 3. Set to “Enabled” for paths that are physically cabled up to trigger the relay in case of a fiber break.