Bihl+Wiedemann BWU Series Modules | BWU1703 PROFIBUS Gateway

Technical Dossier

Product Details And Specifications

Bihl+Wiedemann BWU Series: Comprehensive Module Range and Technical Overview

The Bihl+Wiedemann BWU series represents one of the most widely deployed AS-Interface (AS-i) gateway and master module families in global heavy industry. Installed across chemical processing plants, nuclear facilities, oil refineries, and large-scale manufacturing lines, BWU-series devices serve as the critical communication bridge between AS-Interface field networks and higher-level fieldbus or industrial Ethernet systems. Their deterministic cycle times, robust DIN-rail form factor, and compliance with AS-i Specification Rev. 3.0 have made them a default specification in safety-critical automation projects across Europe, Asia, and North America. The BWU1703 specifically functions as a PROFIBUS DP gateway, enabling AS-i network segments of up to 62 slaves to communicate with Siemens S7, ABB, and other PROFIBUS-based DCS/PLC architectures.

The Evolution of BWU Series Architecture

The BWU product line was introduced by Bihl+Wiedemann in the mid-1990s alongside the commercial rollout of the AS-Interface standard (IEC 62026-2). Early-generation devices such as the BWU1000 and BWU1100 supported AS-i Specification Rev. 2.1, offering 31-slave addressing and basic diagnostic readback over PROFIBUS DP V0. As industrial networks matured, Bihl+Wiedemann released Rev. 3.0-compliant gateways — including the BWU1703 and BWU2405 — that extended addressing to 62 slaves (A/B addressing), integrated safety monitor functionality for AS-i Safety at Work (SaW), and added support for PROFIBUS DP V1 acyclic services. The subsequent generation introduced dual-channel AS-i masters (e.g., BWU3xxx series) and Ethernet-based variants (EtherNet/IP, PROFINET, Modbus TCP), reflecting the industry transition toward IIoT-compatible architectures. Legacy BWU1xxx and BWU2xxx devices remain in active service at brownfield sites where PROFIBUS infrastructure is not scheduled for replacement, creating sustained demand for spare units and certified refurbished stock.

BWU Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed models within the Bihl+Wiedemann BWU gateway and master series. Models are classified by primary fieldbus interface and functional role.

PROFIBUS DP Gateways

• BWU1703: AS-i/PROFIBUS DP gateway, 62-slave Rev. 3.0, single AS-i channel, DIN-rail mount
• BWU1704: AS-i/PROFIBUS DP gateway with integrated AS-i Safety Monitor, SIL 2 certified
• BWU1705: Dual-channel AS-i/PROFIBUS DP gateway, 2 × 62 slaves, extended diagnostic
• BWU1706: AS-i/PROFIBUS DP gateway, IP20, extended address range, DP V1 support
• BWU2405: AS-i/PROFIBUS DP master, 62-slave, integrated power supply 29.5 V DC
• BWU2406: AS-i/PROFIBUS DP master with safety monitor, dual AS-i power feed

DeviceNet Gateways

• BWU1901: AS-i/DeviceNet gateway, 62-slave Rev. 3.0, single channel, 125–500 kbps
• BWU1902: AS-i/DeviceNet gateway with integrated safety monitor, SIL 2

CANopen Gateways

• BWU2101: AS-i/CANopen gateway, 62-slave, NMT master, PDO/SDO mapping
• BWU2102: AS-i/CANopen gateway with safety monitor, dual-channel AS-i

EtherNet/IP & Modbus TCP Gateways

• BWU3455: AS-i/EtherNet/IP gateway, 62-slave, dual-port switch, web diagnostics
• BWU3456: AS-i/EtherNet/IP + Modbus TCP combo gateway, dual AS-i channel
• BWU3457: AS-i/EtherNet/IP gateway with integrated safety monitor, SIL 2, ODVA certified

PROFINET Gateways

• BWU3551: AS-i/PROFINET IO gateway, 62-slave, MRP ring redundancy, GSD file provided
• BWU3552: AS-i/PROFINET IO gateway with safety monitor, PROFIsafe integration, SIL 2

Power Supply & Ancillary Modules

• BWU1001: AS-i power supply unit, 2.4 A, 29.5 V DC, DIN-rail, for BWU gateway pairing
• BWU1002: AS-i power supply unit, 4.0 A, 29.5 V DC, extended load capacity

Sourcing Hard-to-Find & Obsolete BWU Series Parts

Several BWU1xxx and BWU2xxx models have reached end-of-production status, with Bihl+Wiedemann officially discontinuing active manufacturing in favor of the BWU3xxx Ethernet-generation platform. However, the installed base of PROFIBUS-based BWU gateways at refineries, chemical plants, and power generation facilities remains substantial, and full migration to Ethernet fieldbus is not economically viable on short timescales for most operators. DriveKNMS maintains a dedicated inventory of tested, refurbished, and new-old-stock BWU series units specifically to support lifecycle extension programs. Our sourcing network covers original Bihl+Wiedemann stock from authorized channel partners and certified secondary market suppliers across Germany, the Netherlands, and Asia-Pacific. All units are cross-referenced against the original Bihl+Wiedemann part numbering system to prevent counterfeit substitution. For obsolete models such as the BWU1703, BWU1704, BWU1901, and BWU2101, DriveKNMS provides a minimum 12-month warranty on refurbished units and can supply firmware documentation upon request.

Quality Control for the BWU Series Range

BWU-series gateways integrate complex backplane logic, AS-i bus master controllers, and fieldbus transceivers (PROFIBUS ASIC, EtherNet/IP stack) within a compact housing. Standard visual inspection is insufficient for validating functional integrity. DriveKNMS applies a structured test protocol for all BWU units prior to dispatch: (1) Power-on self-test verification against factory LED diagnostic sequence; (2) AS-i bus master scan — the unit is connected to a live AS-i test segment and must successfully detect, address, and cyclically poll a minimum of 4 test slaves; (3) Fieldbus interface validation — PROFIBUS DP units are connected to a Siemens S7-300 test rack and must complete GSD-based configuration and cyclic data exchange without bus errors; (4) Safety monitor function test (for SaW-capable models) — emergency stop input simulation and safe-state output verification; (5) Thermal soak — units operate at 55°C for 2 hours to screen latent component failures. Test records are retained and available upon request for traceability in regulated industries.