Woodhead SST-DN4 Modules: SST-DN4-104-2

Technical Dossier

Product Details And Specifications

Woodhead SST-DN4 Series: Comprehensive Module Range and Technical Overview

The Woodhead SST-DN4 series represents one of the most widely deployed DeviceNet scanner/interface module families in global heavy industry. Originally developed by SST (Synergetic Micro Systems), and later acquired by Woodhead Industries and subsequently Molex, these modules have accumulated a substantial installed base across petrochemical refineries, nuclear power generation facilities, chemical processing plants, and large-scale discrete manufacturing operations. Their integration into Allen-Bradley ControlLogix, SLC 500, PLC-5, and VME-based control architectures made them a de facto standard for DeviceNet network management throughout the 1990s and 2000s. As of 2026, the SST-DN4 series is in its end-of-life phase; however, the installed base remains extensive, and demand for spare and replacement units continues across lifecycle extension programs worldwide.

The Evolution of SST-DN4 Architecture

The SST DeviceNet scanner product line originated in the mid-1990s as industrial fieldbus networks began displacing point-to-point wiring in process automation. The first-generation SST-DN3 modules targeted ISA-bus and VME-bus backplane environments, providing DeviceNet master/slave scanner functionality for early PLC platforms. As Allen-Bradley's ControlLogix platform gained dominance in the early 2000s, Woodhead introduced the SST-DN4 series with native ControlLogix backplane compatibility, supporting the 1756 chassis form factor and communicating over the ControlLogix backplane via the standard module communication protocol.

The SST-DN4-104-2 specifically introduced dual-port DeviceNet scanning capability, allowing a single module slot to manage two independent DeviceNet networks — a critical feature for large-scale systems requiring network segmentation. Firmware revisions across the SST-DN4 lifecycle addressed node count limitations, scan list management, and EDS file compatibility. With the Molex acquisition, firmware development ceased, and the series entered a maintenance-only support posture. Compatibility with RSNetWorx for DeviceNet and Studio 5000 Logix Designer remains functional under legacy configuration workflows, though no new feature development is planned.

SST-DN4 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified, commercially documented models within the Woodhead/SST DeviceNet and related fieldbus scanner product families. Each entry reflects the module's primary functional classification.

SST-DN4-104-2: Dual-port DeviceNet scanner for ControlLogix 1756 chassis, 2 independent networks.
SST-DN4-102: Single-port DeviceNet scanner module for ControlLogix 1756 backplane.
SST-DN4-PCU: DeviceNet scanner for PCI-bus industrial PC platforms, ControlLogix-compatible configuration.
SST-DN4-PCI: PCI-bus DeviceNet interface card for PC-based control and SCADA integration.
SST-DN3-104-2: Dual-port DeviceNet scanner for legacy SLC 500 and PLC-5 backplane environments.
SST-DN3-102: Single-port DeviceNet scanner for SLC 500 series rack-mount applications.
SST-DN3-PCU: DeviceNet scanner for PC-based control, compatible with SLC-era network topologies.
SST-DN3-PCI: PCI-bus DeviceNet interface for industrial PC integration with SLC/PLC-5 systems.
SST-PB3-CLX: PROFIBUS-DP master/slave scanner module for ControlLogix 1756 chassis.
SST-PB3-VME: PROFIBUS-DP interface module for VME-bus backplane industrial control systems.
SST-PFB-SLC: PROFIBUS-DP scanner for SLC 500 rack, master network management.
SST-PFB-PLC5: PROFIBUS-DP interface for Allen-Bradley PLC-5 backplane integration.
SST-DP4-PCI: PROFIBUS-DP PCI-bus interface card for PC-based HMI and SCADA systems.
SST-ESR2-CLX-RLL: EtherNet/IP scanner module for ControlLogix, relay ladder logic configuration support.
SST-SR4-CLX-RLL: Serial communication module for ControlLogix, multi-protocol RS-232/RS-485 support.

Sourcing Hard-to-Find & Obsolete SST-DN4 Parts

DriveKNMS maintains a dedicated inventory program for end-of-life Woodhead SST-DN4 and related series modules. As Molex has formally discontinued new production and active support for this product family, the primary supply channel for replacement units is the secondary market. DriveKNMS sources SST-DN4-104-2 and related models through decommissioned plant asset recovery, authorized distributor overstock liquidation, and direct procurement from facilities undergoing control system migration.

All units are catalogued by firmware revision, hardware revision, and physical condition grade prior to listing. For customers operating extended lifecycle programs — particularly in nuclear, refinery, or chemical plant environments where control system replacement is constrained by regulatory approval timelines — DriveKNMS provides documented unit history, functional test reports, and long-term reservation agreements to support multi-year maintenance planning.

Quality Control for the SST-DN4 Range

The SST-DN4 series presents specific test challenges due to its backplane communication architecture and dual-network scanning capability. DriveKNMS applies a structured validation protocol to each unit prior to dispatch. Functional testing is performed using a live ControlLogix 1756 chassis with verified firmware, confirming backplane enumeration, DeviceNet network initialization on both ports (for dual-port models), and scan list execution against a reference node set. Communication integrity is verified at 125 Kbps, 250 Kbps, and 500 Kbps baud rates. Firmware version is read and recorded. Physical inspection covers backplane connector pin condition, faceplate port integrity, and LED indicator function. Units that fail any test stage are quarantined and not listed for sale.