OLMG12 Single-mode Fiber Optic

The Siemens PROFIBUS OLM/G12 supports single-mode fiber optic cables (9/125µm or 10/125µm) via BFOC interfaces for long-distance industrial PROFIBUS networks.

Overview

The OLM/G12 (Optical Link Module) is designed to convert electrical PROFIBUS RS-485 signals into optical signals and vice versa, enabling reliable communication over long distances in industrial environments . It supports bus, star, and redundant ring topologies, making it suitable for applications such as traffic control systems, road tunnels, and other automation networks .

Single-mode Fiber Compatibility

• Supported fiber types: Single-mode or mono-mode glass fiber optic cables with 9/125µm or 10/125µm core/cladding .
• Connector type: BFOC (Bajonett Fiber Optic Connector), functionally compatible with ST connectors .
• Interfaces: The OLM/G12 includes 2 glass fiber optic interfaces (4 BFOC plugs) and 1 RS-485 interface for electrical connections .

Technical Specifications

• Distance capability: Up to 3000 meters with plastic fiber optic cables; single-mode fibers can achieve longer distances depending on optical power and network design .
• Data rates: Automatically detects all PROFIBUS data rates from 9.6 kbit/s to 12 Mbit/s, including 45.45 kbit/s for PROFIBUS PA .
• Redundancy: Supports redundant power supply and wiring, enabling high availability and rapid fault localization via signaling contacts and LED indicators .
• Environmental range: Standard OLM/G12 operates from 0°C to 60°C, while the OLM/G12-EEC variant supports –20°C to +60°C with up to 100% humidity .

Installation and Operation

• Mounting: Can be installed on a DIN rail or mounting plate .
• Network setup: Supports linear, star, and ring topologies, including redundant optical rings .
• Monitoring: Each optical channel has a measurement output to detect input levels with a standard voltmeter, and LEDs indicate operational status and faults .
• Maintenance: Cleaning and fault handling procedures are provided in the operating manual to ensure reliable long-term operation .

Applications

The OLM/G12 is ideal for industrial automation networks requiring long-distance, high-reliability communication, particularly in environments where electromagnetic interference or harsh conditions make optical transmission preferable over copper cabling . In summary, the OLM/G12 module provides a robust solution for integrating single-mode fiber optics into PROFIBUS networks, offering flexible topologies, long-distance communication, and high operational reliability.