ABB RETA-02

Technical Dossier

Product Details And Specifications

ABB RETA Series Technical Notes

The ABB RETA series comprises dedicated EtherNet/IP and Modbus TCP communication adapter modules engineered for integration with ABB's ACS and ACH series variable frequency drives (VFDs). These adapters serve as the fieldbus interface layer between ABB drives and industrial Ethernet networks, enabling real-time process control, parameter read/write, and diagnostic data exchange over standard TCP/IP infrastructure.

The Evolution of RETA Architecture

The RETA series was introduced as ABB transitioned its drive communication strategy from proprietary fieldbus protocols (DDCS, RDCO fiber optic) toward open industrial Ethernet standards. Early ABB drives relied on RDCO optical modules and RMIO control boards with dedicated serial links. The RETA series represented the shift to plug-in adapter slots on the drive's option board interface, standardizing the physical and logical connection method across drive families.

First generation (RETA-01): Introduced EtherNet/IP and Modbus TCP support for ACS600 and early ACS800 platforms. Used a 10/100 Mbps auto-negotiating RJ45 port. Configuration was performed via drive parameters and a dedicated PC tool.

Second generation (RETA-02): Extended compatibility to ACS800, ACS850, ACS550, ACS355, and ACH550 platforms. Improved parameter mapping, added explicit messaging support for EtherNet/IP, and introduced dual-port topology options in some firmware revisions. The RETA-02 remains the most widely deployed model in the installed base.

Current generation adapters: For ACS880 and ACH580 platforms, ABB transitioned to the FENA series (FENA-01, FENA-11, FENA-21), which offer dual-port EtherNet/IP with Device Level Ring (DLR) support, integrated web server diagnostics, and conformance to EtherNet/IP Adapter Device Profile. RETA-02 units are not forward-compatible with FENA-slot drives without a mechanical and firmware migration.

The compatibility boundary between RETA and FENA generations is a critical planning factor for plant engineers managing mixed-generation drive fleets. RETA-02 units installed in ACS800 drives operating in legacy DCS environments (Honeywell Experion, Emerson DeltaV, Yokogawa CENTUM) are typically retained rather than replaced due to the cost and risk of re-commissioning validated control loops.

RETA Series Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified RETA and directly related ABB drive Ethernet adapter catalog. Each entry reflects a distinct hardware revision or platform-specific variant:

RETA-01: EtherNet/IP & Modbus TCP adapter for ACS600/ACS800, 10/100 Mbps, first-generation slot mount.
RETA-02: EtherNet/IP & Modbus TCP adapter for ACS800/ACS550/ACS355/ACH550, auto-negotiating RJ45, most widely deployed RETA variant.
RETA-02C: RETA-02 with conformal coating for high-humidity and corrosive-atmosphere installations.
FENA-01: Single-port EtherNet/IP adapter for ACS880/ACH580, successor to RETA-02 on new-generation drives.
FENA-11: Dual-port EtherNet/IP adapter with DLR support for ACS880/ACH580, ring topology capable.
FENA-21: Dual-port EtherNet/IP + Modbus TCP combined adapter for ACS880/ACH580 platforms.
RETA-02 (3AUA0000024828): OEM part number variant of RETA-02, used in ABB factory-configured drive packages.
RETA-02 (3AFE68905782): Alternate ABB catalog reference for RETA-02, used in European distribution channels.
RDCO-01: DDCS fiber optic communication module for ACS600/ACS800, predecessor to Ethernet-based RETA adapters.
RDCO-02: Extended DDCS fiber optic module with additional channel support, used in multi-drive DDCS ring configurations.
RDCO-03: DDCS module with enhanced diagnostics, compatible with ACS800 multidrive systems.
RMIO-11: Control board for ACS800 with integrated I/O; pairs with RETA-02 for Ethernet-enabled drive control.
RMIO-02: Standard ACS800 control board, base platform for RETA-02 adapter installation.
RAIO-01: Analog I/O extension module for ACS800, used alongside RETA-02 in expanded I/O configurations.
RDIO-01: Digital I/O extension module for ACS800, complements RETA-02 in discrete control applications.
RPBA-01: PROFIBUS DP adapter for ACS800/ACS550, alternative fieldbus option to RETA-02 in PROFIBUS plants.
RCAN-01: CANopen adapter for ACS800, used in mobile machinery and smaller automation networks.
RCNA-01: ControlNet adapter for ACS800, deployed in Rockwell Automation ControlNet architectures.

Quality Control for the RETA Series Range

RETA-02 and related adapter modules are tested against a defined protocol prior to dispatch. The adapter's RJ45 port and internal MAC address are verified using a network analyzer. EtherNet/IP explicit and implicit messaging functions are validated by connecting the adapter to a test drive (ACS800 with RMIO control board) and executing parameter read/write cycles via a Rockwell Studio 5000 or Codesys EtherNet/IP scanner. Modbus TCP register mapping is verified against ABB's published parameter address tables.

The adapter's option slot connector pins are inspected under magnification for corrosion, bent contacts, and solder joint integrity. Firmware version is read and recorded. Units with firmware below the minimum recommended revision for the target drive platform are flagged and either updated or excluded from shipment. Conformal-coated variants (RETA-02C) are inspected for coating integrity under UV light prior to dispatch.