ABB RLM01 Modules: RLM01/3BDZ000398R1

Technical Dossier

Product Details And Specifications

ABB RLM01 Series: Comprehensive Module Range and Technical Overview

The ABB RLM01 series represents a dedicated line of link and communication interface modules developed for ABB's industrial automation platforms, including the Advant OCS, MOD 300, and Symphony Plus (S+ Operations / S+ Engineering) distributed control systems. These modules are deployed across critical process industries — petroleum refineries, chemical processing plants, nuclear power generation facilities, and large-scale utilities — where deterministic fieldbus communication and high-availability backplane integration are non-negotiable requirements. The RLM01 family, identified by the base part number prefix 3BDZ000398R1, provides the physical and logical link layer between controller nodes, I/O clusters, and supervisory networks within ABB's proprietary AF100 and MasterBus 300 communication architectures. Installed base across global heavy industry is substantial, with many sites maintaining these systems well beyond the original product lifecycle, making reliable spare parts sourcing a critical operational concern.

The Evolution of RLM01 Architecture

The RLM01 module line emerged from ABB's consolidation of its Asea Brown Boveri and Bailey Controls automation portfolios in the early 1990s. The initial architecture was designed around the MasterBus 300 token-passing fieldbus, operating at 2.5 Mbit/s over coaxial or fiber-optic media. This bus topology was engineered for deterministic cycle times in process control loops, a requirement that distinguished it from general-purpose industrial Ethernet of the same era.

Through the mid-1990s to early 2000s, ABB evolved the RLM01 hardware to support dual-redundant communication paths, addressing the high-availability demands of continuous-process industries. The module's firmware was updated to handle increased node counts as plant expansions required larger DCS topologies. Compatibility with the AF100 fieldbus (a derivative architecture used in Advant Controller 450 and AC 160 platforms) was introduced, extending the RLM01's applicability across a broader range of ABB controller families.

By the 2010s, ABB's strategic direction shifted toward the Symphony Plus platform and Ethernet-based communication (IEC 61850, PROFINET). The RLM01 series entered its maintenance and end-of-life phase. ABB formally discontinued active production of several RLM01 variants, transitioning customers toward the RCI800 and CI858 communication interface modules for new installations. However, the installed base of RLM01-dependent systems remains large, and direct hardware replacement without full DCS migration is the standard maintenance strategy for most operators.

RLM01 Full Catalog & Functionalities (SKU List)

The following SKUs represent the documented RLM01 series and closely associated link/communication modules within the ABB Advant / Symphony ecosystem. Modules are categorized by primary function.

Link & Communication Interface Modules

• RLM01 / 3BDZ000398R1: MasterBus 300 link module; primary node interface for AF100 fieldbus communication.
• RLM01 / 3BDZ000398R2: Revised hardware revision of 3BDZ000398R1; improved EMC compliance, same functional specification.
• RCOM / 3BSE015488R1: Remote communication module; supports serial and parallel data exchange between Advant controller nodes.
• RCOM / 3BSE015488R2: Second hardware revision; extended temperature tolerance for harsh environment enclosures.
• CI810B / 3BSE020520R1: AF100 fieldbus communication interface; connects AC 800M controller to AF100 I/O clusters.
• CI820V1 / 3BSE025255R1: PROFIBUS DP master communication interface for S800 I/O integration.
• CI840A / 3BSE041882R1: AF100 redundant communication interface; dual-channel link for high-availability configurations.
• CI858K01 / 3BSE018135R1: DriveBus communication interface; links AC 800M to ABB drives via proprietary DriveBus protocol.

Controller & CPU Modules (Compatible Platform)

• PM861AK01 / 3BSE018157R1: AC 800M main processor module; primary CPU for Symphony Plus controller cabinets.
• PM864A / 3BSE018161R1: High-performance AC 800M processor; supports extended I/O node counts and redundant configurations.
• PM865K01 / 3BSE031151R1: AC 800M processor with extended memory; used in large-scale DCS topologies.
• PM866K01 / 3BSE050198R1: Latest-generation AC 800M CPU; supports IEC 61131-3 programming and Symphony Plus integration.

Digital I/O Modules (S800 Series — RLM01 Compatible Clusters)

• DI810 / 3BSE008508R1: 24 VDC digital input module; 16-channel, used in S800 I/O stations linked via AF100.
• DO810 / 3BSE008514R1: 24 VDC digital output module; 16-channel, relay-isolated outputs.
• AI810 / 3BSE008516R1: Analog input module; 8-channel, 4–20 mA / 0–10 V, 12-bit resolution.
• AO810V2 / 3BSE038415R1: Analog output module; 8-channel, 4–20 mA, updated isolation design.
• DI811 / 3BSE008552R1: 120 VAC digital input module; 16-channel, for high-voltage field signal integration.

Power Supply Modules

• SD821 / 3BSC610037R1: 24 VDC power supply module for S800 I/O stations; 5 A rated output.
• SD822 / 3BSC610038R1: 24 VDC redundant power supply; dual-feed configuration for continuous-process availability.

Sourcing Hard-to-Find & Obsolete RLM01 Parts

The RLM01/3BDZ000398R1 and its associated hardware revisions are no longer in active ABB production. Lead times through standard distribution channels are indeterminate, and OEM new-old-stock (NOS) inventory is exhausted at most authorized distributors. DriveKNMS maintains a dedicated inventory of tested RLM01 series modules sourced from decommissioned DCS installations, controlled plant shutdowns, and verified secondary market channels.

For operators running Advant OCS, MOD 300, or early Symphony Plus systems, the practical options are: (1) direct hardware replacement with a tested RLM01 equivalent, (2) a controlled migration to CI810B or CI840A communication interfaces where backplane compatibility permits, or (3) full controller migration to AC 800M with Symphony Plus — a multi-year capital project. For sites where option 3 is not yet funded, DriveKNMS provides lifecycle extension support through verified spare module supply, covering the RLM01 series and the full range of associated S800 I/O and communication modules listed above.

All modules are supplied with full traceability documentation, including source records and pre-shipment test reports. Emergency dispatch is available for unplanned outage scenarios.

Quality Control for the RLM01 Range

The RLM01 module integrates directly into the ABB Advant backplane bus, making backplane connector integrity and bus termination resistance critical parameters. DriveKNMS applies the following test protocol to all RLM01 units prior to dispatch:

• Visual and mechanical inspection: PCB condition, connector pin integrity, conformal coating assessment, and housing latch function.
• Backplane bus communication test: Module is installed in a live ABB Advant test rack. MasterBus 300 token acquisition, node addressing, and cyclic data exchange are verified against reference controller.
• AF100 link layer verification: Frame transmission and reception at 2.5 Mbit/s are confirmed. Error counters are monitored over a minimum 30-minute soak period.
• Firmware version check: Installed firmware revision is recorded and compared against ABB's last published revision for the hardware variant.
• Power consumption measurement: Module current draw on the 5 VDC and 24 VDC backplane rails is measured and compared against ABB specification limits.
• Thermal soak test: Module operates at rated load for 2 hours at 50°C ambient to screen for latent component failures.

Test results are documented per unit and supplied with each shipment.