Honeywell 9904 Series Modules – 9904-TPR

Technical Dossier

Product Details And Specifications

Honeywell 9904 Series Technical Notes

The Honeywell 9904 Series represents a core component family within Honeywell's TDC 3000 and PlantScape/Experion distributed control system (DCS) infrastructure. Deployed extensively across global heavy industry — including petrochemical refineries, nuclear power facilities, offshore platforms, and large-scale chemical processing plants — the 9904 Series provides the physical-layer coaxial network interface and signal distribution backbone that underpins plant-wide data highways. Installations of this series are documented across facilities in North America, the Middle East, and Asia-Pacific, where long operational lifecycles (15–30 years) make spare parts availability a critical procurement concern. The series covers coaxial tap assemblies, termination modules, and associated signal-path hardware that maintain the integrity of Honeywell's proprietary Data Highway Plus (DH+) and Local Control Network (LCN) coaxial bus architectures.

The Evolution of 9904 Series Architecture

The 9904 Series was introduced alongside Honeywell's TDC 3000 platform in the early 1980s, designed to serve the coaxial segment of the Local Control Network (LCN) — a 5 Mbps token-passing bus that interconnected Universal Stations, History Modules, Application Modules, and Network Interface Modules. The physical medium was RG-6 or RG-11 coaxial cable, and the 9904 tap assemblies provided the passive directional coupling required to branch node connections off the main trunk without signal reflection or impedance mismatch.

Through the 1990s, as Honeywell transitioned toward the PlantScape and later Experion PKS platforms, the LCN coaxial infrastructure remained in service at the majority of installed base sites due to the prohibitive cost of full migration. The 9904 Series hardware was retained as-is, with Honeywell issuing compatibility bulletins confirming continued support. By the 2000s, the series entered a maintenance-only lifecycle phase: no new design revisions were released, and production volumes declined sharply. By approximately 2010–2015, most 9904 Series part numbers were formally discontinued by Honeywell, transitioning the entire catalog to aftermarket and refurbished supply channels. Sites running TDC 3000 LCN infrastructure today — estimated at several hundred globally — depend entirely on third-party distributors for 9904 Series replenishment.

9904 Series Full Catalog & Functionalities (SKU List)

The following part numbers represent verified SKUs within the Honeywell 9904 coaxial network hardware family. Each entry reflects a distinct mechanical or electrical configuration used in LCN trunk and drop cable assemblies:

9904-TPR: Coaxial tap assembly with right-angle BNC connector for LCN trunk branch connections.
9904-TP: Standard coaxial tap assembly, straight BNC configuration, LCN trunk interface.
9904-TPS: Coaxial tap assembly, short-body variant for space-constrained cabinet installations.
9904-CN: Coaxial cable assembly, node drop segment, pre-terminated with BNC connectors.
9904-CNR: Coaxial cable assembly, right-angle termination variant for panel-mount node drops.
9904-TR: LCN trunk terminator, 75-ohm impedance, end-of-segment bus termination.
9904-TRM: Trunk terminator module with integrated mounting bracket for DIN rail installation.
9904-CB: Coaxial bulkhead connector assembly for cabinet wall feedthrough applications.
9904-CBR: Right-angle bulkhead coaxial connector, panel-mount, LCN signal feedthrough.
9904-EX: LCN coaxial extender assembly for segment length extension beyond standard 300m limit.
9904-JB: Junction box assembly for coaxial tap consolidation at field distribution points.
9904-SH: Coaxial shield grounding assembly, single-point ground for LCN trunk shielding.
9904-AD: BNC-to-N-type coaxial adapter for test equipment interface during LCN diagnostics.
9904-CAP: Dust cap assembly for unused BNC tap ports on 9904-TP and 9904-TPR units.
9904-KIT: Field installation kit including tap, terminators, and cable assemblies for one LCN node drop.
9904-LBL: Cable identification label set, pre-printed for 9904 Series coaxial segment documentation.
9904-WRP: Weatherproof wrap kit for outdoor or high-humidity coaxial tap installations.

Quality Control for the 9904 Series Range

All 9904 Series units processed by DriveKNMS undergo a standardized inspection and test protocol prior to dispatch. Passive coaxial components — taps, terminators, and cable assemblies — are evaluated using a vector network analyzer (VNA) to verify insertion loss, return loss, and impedance conformance across the 1–100 MHz frequency range relevant to LCN operation. BNC connector interfaces are inspected under 10x magnification for pin straightness, dielectric integrity, and shell plating condition. Terminator resistances are measured to confirm 75-ohm ±1% tolerance. Cable assemblies are continuity-tested end-to-end and subjected to a 500V DC hipot test to verify dielectric withstand. Units exhibiting any out-of-tolerance parameter are quarantined and not offered for sale. Each shipped unit is individually bagged with a test record card documenting measured values and inspection date.