ABB RDO86 Modules

Technical Dossier

Product Details And Specifications

ABB RDO86 Series: Comprehensive Module Range and Technical Overview

The ABB RDO86 series is a family of digital relay output modules engineered for deployment within ABB's Advant OCS / Master distributed control system (DCS) architecture. These modules occupy a critical role in heavy industrial installations worldwide, including petrochemical refineries, nuclear power facilities, offshore platforms, and large-scale chemical processing plants. The RDO86 range provides hardened, relay-isolated discrete output capability, enabling field-level actuation of solenoids, motor starters, and on/off control valves directly from the DCS controller layer. Their robust design and proven field reliability have made them a long-term fixture in plant asset inventories where system continuity over multi-decade operational lifespans is mandatory.

The Evolution of RDO86 Architecture

The RDO86 series was developed as part of ABB's Advant Controller 400 series ecosystem, which entered widespread industrial deployment during the late 1980s and through the 1990s. The architecture is based on the Advant Fieldbus 100 (AF100) and RCOM communication backplane standards, allowing modular I/O expansion within S100 I/O subrack assemblies. Early variants of the RDO86 provided 8-channel relay output configurations, while subsequent revisions introduced 16-channel density (e.g., RDO86-16L) to reduce subrack slot consumption in high-channel-count applications.

Compatibility across the RDO86 family is governed by the S100 I/O bus standard. Modules interface with processor units such as the PM864, PM865, and PM866 via the CI854 PROFIBUS DP communication interface or direct S100 backplane addressing. As ABB transitioned its DCS portfolio toward the System 800xA platform, the RDO86 series entered a maintenance and lifecycle extension phase. The modules remain fully supported as spare parts for installed base continuity, though new greenfield deployments now utilize the S800 I/O family (e.g., DO810, DO820) as the designated successor architecture.

RDO86 Full Catalog & Functionalities (SKU List)

The following SKUs represent the documented RDO86 series module range within the ABB S100 I/O system. Each entry is classified by function and channel configuration:

Digital Relay Output Modules:

• RDO86-16L: 16-channel relay output module, low-current contacts, S100 bus, 24 VDC logic
• RDO86-8: 8-channel relay output module, standard contact rating, S100 I/O subrack mount
• RDO86-16: 16-channel relay output, standard contact load, S100 backplane interface
• RDO86-16H: 16-channel relay output, high-current contact variant, for motor starter applications
• RDO86-8L: 8-channel relay output, low-current contacts, reduced power consumption design

Associated S100 Digital Input Modules (same subrack ecosystem):

• RDI86-16: 16-channel digital input module, 24 VDC, S100 bus compatible
• RDI86-8: 8-channel digital input, 24 VDC, standard S100 I/O format
• RDI86-16H: 16-channel digital input, high-voltage field signal variant (120 VAC)
• RDI86-8H: 8-channel digital input, 120 VAC field signal, S100 subrack

Analog Output Modules (co-deployed with RDO86 in mixed I/O subracks):

• RAO86-4: 4-channel analog output, 4–20 mA, 12-bit resolution, S100 bus
• RAO86-8: 8-channel analog output, 4–20 mA, S100 backplane interface

Analog Input Modules:

• RAI86-4: 4-channel analog input, 4–20 mA / 0–10 V, S100 I/O
• RAI86-8: 8-channel analog input, multi-range, S100 bus compatible
• RAI86-16: 16-channel analog input, high-density configuration, S100 subrack

Communication & Processor Modules (subrack infrastructure):

• CI854: PROFIBUS DP communication interface for S100 I/O to AC800M controller
• CI854A: Revised PROFIBUS DP interface, extended diagnostics, S100 compatible
• PM864A: Advant Controller 800 series processor module, primary CPU for RDO86 subrack systems

Sourcing Hard-to-Find & Obsolete RDO86 Parts

The RDO86 series has been classified as a mature/end-of-production product line by ABB. OEM new stock availability through standard distribution channels is severely limited or exhausted for most variants. DriveKNMS maintains a dedicated inventory program for S100 I/O lifecycle extension, sourcing RDO86 modules through certified industrial surplus channels, decommissioned plant asset recovery, and long-term warehousing partnerships.

All RDO86 units in DriveKNMS inventory are catalogued by hardware revision level and firmware compatibility to ensure correct fit within the customer's existing Advant or System 800xA installed base. For plants operating under long-term service agreements (LTSA) or multi-year maintenance contracts, DriveKNMS offers reserved stock allocation and priority fulfillment for RDO86 and associated S100 I/O modules. Customers are advised to provide their existing module revision markings and subrack configuration details when submitting sourcing requests to ensure cross-compatibility.

Quality Control for the RDO86 Range

RDO86 relay output modules undergo a structured multi-stage inspection protocol at DriveKNMS prior to shipment. Given the complexity of the S100 backplane bus interface and the relay contact array, the following procedures are applied:

• Visual and mechanical inspection: PCB surface examination for corrosion, relay coil condition, connector pin integrity, and housing damage assessment.
• Backplane bus communication test: Module is seated in a reference S100 subrack and addressed via CI854 interface to verify correct register mapping and diagnostic response.
• Relay contact functional test: Each output channel is individually energized and de-energized under controlled load. Contact resistance is measured and logged against ABB factory specification thresholds.
• Insulation resistance test: Relay contact isolation is verified between channels and between contacts and logic circuitry to confirm field-side isolation integrity.
• Burn-in cycle: Modules are subjected to a thermal cycling burn-in period to screen for latent component failures prior to dispatch.

Test records are retained and available upon request for quality-critical applications in regulated industries (nuclear, refining, pharmaceutical).

For RDO86 sourcing inquiries, technical compatibility questions, or bulk spare parts requirements:

• Email: [email protected]
• WhatsApp: +86 18359293191
• Web: driveknms.com