Honeywell TK-PRS021 Control Processor Module TPS/TDC 3000 Series

Technical Dossier

Product Details And Specifications

Honeywell TK (TPS/TDC 3000) Series Technical Notes

The Honeywell TK-series, deployed under the TotalPlant Solution (TPS) and TDC 3000 distributed control system (DCS) platforms, represents one of the most widely installed process automation architectures in global heavy industry. Refineries, petrochemical complexes, nuclear power facilities, and LNG terminals across North America, Europe, and Asia-Pacific have relied on TK-series hardware for continuous process control since the 1980s. The installed base remains substantial: tens of thousands of nodes remain in active service, making spare parts availability a critical operational concern for plant engineers and maintenance managers worldwide.

The TK-PRS021 is a Control Processor Module within this ecosystem, responsible for executing control strategies, managing scan cycles, and coordinating data exchange across the Universal Control Network (UCN) and Local Control Network (LCN). Its role is central to loop execution integrity in TPS-based process units.

The Evolution of TK-Series Architecture

The TK-series hardware lineage traces directly to Honeywell's TDC 2000 platform (introduced 1975), which established the foundational concept of distributed process control. TDC 3000 followed in 1983, introducing the Local Control Network (LCN) as a high-speed token-passing data highway operating at 5 Mbps. The Universal Control Network (UCN) was subsequently introduced to connect field-level process managers to the LCN backbone.

Key architectural milestones include: the transition from AM (Application Module) to PM (Process Manager) as the primary controller node; the introduction of HPM (High-Performance Process Manager) for faster scan rates; and the eventual migration path toward Experion PKS (Process Knowledge System), Honeywell's current-generation DCS platform. TK-series modules are not natively compatible with Experion PKS without gateway hardware or full migration projects, creating a long-term dependency on original TK-series spare parts for sites that have not completed platform upgrades.

Compatibility considerations are significant: TK-series backplanes, power supplies, and communication modules are generation-specific. Mixing hardware revisions without firmware validation can cause node failures or scan cycle disruptions. Plants operating mixed TDC 3000 / TPS environments must maintain strict revision control across all replacement modules.

TK-Series Full Catalog & Functionalities (SKU List)

The following SKUs represent commonly sourced modules within the Honeywell TK / TPS / TDC 3000 ecosystem, organized by functional category:

Control Processors & Application Modules

• TK-PRS021: Control Processor Module — executes control strategies and manages UCN/LCN data exchange in TPS process units.
• TK-PRR021: Redundant Control Processor Module — paired redundancy configuration for high-availability loop control.
• TK-PPP001: Process Point Processor — handles analog and digital point processing within the PM node.
• TK-FTEB01: Fault-Tolerant Ethernet Bridge — provides Ethernet connectivity for TPS nodes in modernized network environments.
• TK-PRS011: Earlier-generation Control Processor Module — predecessor to TK-PRS021, lower memory capacity.

I/O Modules — Analog

• TK-AIM001: Analog Input Module — 16-channel, 4–20 mA input, used in PM and HPM nodes.
• TK-AOM001: Analog Output Module — 8-channel, 4–20 mA output for final control element interfacing.
• TK-AIM051: High-density Analog Input Module — 32-channel configuration for high point-count applications.
• TK-AOM051: High-density Analog Output Module — 16-channel output expansion for large process units.

I/O Modules — Digital

• TK-DIM001: Digital Input Module — 32-channel, 24 VDC discrete input for status and interlock monitoring.
• TK-DOM001: Digital Output Module — 32-channel, 24 VDC discrete output for solenoid and relay actuation.
• TK-DIM051: High-density Digital Input Module — 64-channel configuration for large I/O marshalling cabinets.

Communication & Network Modules

• TK-CCR001: Control Communication Router — manages data routing between UCN segments and LCN highway.
• TK-LCN001: LCN Interface Module — provides node-level connection to the 5 Mbps Local Control Network token ring.
• TK-UCN001: UCN Coax Interface Module — coaxial UCN physical layer interface for PM and HPM nodes.

Power Supply Modules

• TK-PSA001: AC Power Supply Module — 120/240 VAC input, regulated DC output for TPS node backplanes.
• TK-PSR001: Redundant Power Supply Module — hot-standby power redundancy for critical process nodes.

Sourcing Hard-to-Find & Obsolete TK-Series Parts

Honeywell formally transitioned TDC 3000 and TPS hardware to end-of-life status, with standard support and new manufacture discontinued for the majority of TK-series modules. This creates a structural supply gap for the large installed base that has not yet migrated to Experion PKS.

Quality Control for the TK-Series Range

TK-series modules present specific testing challenges due to their proprietary backplane bus architecture and token-passing network communication protocols. Standard bench power-up procedures are insufficient to validate module functionality in isolation.

DriveKNMS applies the following verification procedures to all TK-series inventory:

All tested modules are issued a DriveKNMS inspection report documenting test date, firmware revision, and pass/fail results by test category.