Hirschmann MR 8-03 24V DC Industrial Modular Bridge/Router
Product Overview
The Hirschmann MR 8-03 (24V DC) is a legacy, heavy-duty industrial modular bridge/router designed by Hirschmann (a Belden brand) for field-level sub-network interconnection.
Built specifically to link industrial Ethernet and fieldbus communication segments over 24V DC auxiliary power systems, the MR 8-03 provides localized traffic filtering, protocol bridging, and routing between control cells, field devices, and higher-level automation networks.
Featuring a rugged metal chassis and fanless architecture, the MR 8-03 is engineered for panel-mounting in harsh control room and electrical substation environments where continuous operation and high noise immunity are required.
Technical Parameter List
| Parameter | Specification Details |
| Product Model | MR 8-03 |
| Product Type | Modular Industrial Bridge / Router |
| Manufacturer | Hirschmann (Belden) |
| Operating Voltage | 24 V DC (Industrial Low-Voltage Input) |
| Architecture | Modular expansion slots for Ethernet/Fieldbus media interfaces |
| Cooling | Passive convection (Fanless design) |
| Dimensions (W × H × D) | ~51 mm × 178 mm × 152 mm (2.0 in × 7.0 in x 6.0 in) |
| Weight | ~3.2 kg (7.0 lbs) |
| Enclosure / Housing | Heavy-duty metal industrial housing |
| Country of Origin | Germany |
Key Features & Core Advantages
Cell Isolation & Traffic Filtering: Functions as a network bridge/router to segment local plant traffic, preventing local broadcast storms from flooding the main control backbone.
Modular Interface Flexibility: Accommodates interchangeable communication expansion modules to adapt to various copper and optical fiber cabling standards.
Industrial 24V DC Power Standard: Integrates directly with standard 24V DC control cabinet power supplies without requiring external AC adapters.
Fanless Convection Cooling: Operates reliably without mechanical moving parts, preventing airborne dust ingress and enhancing overall mean time between failures (MTBF).
High EMC Immunity: Built with heavy metal shielding to resist high electromagnetic interference (EMI), electrostatic discharge, and electrical surges common in motor control centers.
Model Classification & Hardware Architecture
The MR series represents Hirschmann’s legacy modular bridge and routing platform:
MR 8-03 (Base Unit): Main modular bridge/router controller frame operating on 24V DC power.
Expansion Modules (Option Cards): Slide-in interface cards for multi-mode/single-mode fiber optics, AUI, and 10Base-T/100Base-TX twisted-pair copper interfaces.
Power Variants: Configured for standard 24V DC control power or optional wide-range AC/DC substation power inputs.
Environmental Tolerance Conditions
| Condition | Rating / Standard |
| Operating Temperature | $0^\circ\text{C}$ to $+55^\circ\text{C}$ ($32^\circ\text{F}$ to $131^\circ\text{F}$) |
| Storage Temperature | $-20^\circ\text{C}$ to $+70^\circ\text{C}$ ($-4^\circ\text{F}$ to $158^\circ\text{F}$) |
| Relative Humidity | 10% to 95% (non-condensing) |
| Vibration Resistance | IEC 60068-2-6 compliant |
| Shock Resistance | IEC 60068-2-27 compliant |
| Electromagnetic Compatibility (EMC) | EN 55022 Class A, EN 61000-4 series industrial noise immunity |
Installation Method
Safety Notice: Always ensure power supplies are shut off and proper electrostatic discharge (ESD) protection is used when handling internal modules.
Panel Mounting: Secure the MR 8-03 chassis onto a backpanel or mounting plate inside the control cabinet using the provided mounting flange holes.
Grounding: Connect a heavy-gauge protective earth (PE) grounding cable to the chassis ground stud to ensure proper EMI shielding.
Module Insertion: Insert any required interface expansion cards into the module slots until the backplane connector locks, then tighten the front panel retaining screws.
Power Wiring: Connect the $+24\text{ V DC}$ and $0\text{ V DC}$ power leads into the screw terminal block on the unit, verifying correct polarity before energizing.
Network Connections: Attach RJ45 copper or ST/SC fiber optical cables to the active module front ports.
Operating Instructions
Power-On Verification: Apply 24V DC power to the terminal block. Observe the main status LEDs on the front panel to ensure internal diagnostic checks pass.
Status LEDs:
Power / Ready LED: Solid green indicates stable 24V DC input and normal internal firmware operation.
Port Activity LEDs: Blinking green indicates active packet forwarding across connected subnetworks.
Fault LED: Red indicates link loss or internal system fault condition.
Configuration & Maintenance: Access routing tables, bridging parameters, and port filters via the serial management console or diagnostic software utility.