ABB RETA-01 Retrofit-Compatible Ethernet Adapter for Legacy Systems

ABB RETA-01 Retrofit-Compatible Ethernet Adapter for Legacy Systems

The ABB RETA-01 is a dedicated Ethernet adapter module designed for integration with ABB’s ACS800 and ACS600 series variable frequency drives. As industrial facilities face increasing pressure to modernize aging automation infrastructure without full system replacement, the RETA-01 serves as a critical bridge component — enabling legacy drive platforms to communicate over modern Ethernet-based fieldbus networks including Modbus TCP/IP and EtherNet/IP. For maintenance engineers and system integrators managing retrofit projects, the RETA-01 offers a cost-effective, low-disruption path to extend the operational life of existing drive cabinets while aligning them with current SCADA, DCS, and PLC communication architectures.

In many brownfield automation environments, the primary challenge is not the drive itself but the communication gap between older DDCS-based drive systems and modern Ethernet-capable controllers. The RETA-01 resolves this gap directly. It mounts into the option slot of compatible ACS800 drive units and provides a standard RJ-45 Ethernet port, allowing the drive to participate in plant-wide Ethernet networks without requiring a full drive replacement. This makes it especially valuable in facilities where the ACS800 drive hardware remains mechanically sound but the control architecture has been upgraded to a newer Siemens S7-1500, Allen-Bradley ControlLogix, or Schneider Electric Modicon M340 platform that communicates exclusively over Ethernet.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

Successful integration of the RETA-01 into a legacy drive system begins well before the module arrives on site. Retrofit planning must account for several interdependent factors that, if overlooked, can extend commissioning time or introduce compatibility issues during cutover.

Option Slot Verification: The ACS800 drive family supports multiple option modules simultaneously, but slot availability must be confirmed before ordering. In drives already populated with an RDCO-03 DDCS communication module or an RAIO-01 analog I/O extension, the target slot must be identified and cleared if necessary. Drives using the RTAC-01 pulse encoder interface for closed-loop speed control must retain that module, so the RETA-01 must occupy a different available slot.

Power Budget Assessment: Each option slot draws power from the drive’s internal supply. When multiple option modules are installed — such as a combination of the RETA-01, an RDIO-01 digital I/O extension, and a fieldbus adapter — the total current draw must remain within the drive’s option slot power budget. Exceeding this limit can cause intermittent faults or module resets under load. Review the drive’s hardware manual for slot power ratings before finalizing the module configuration.

Terminal and Backplane Interface: Unlike external communication gateways that require separate DIN rail mounting and additional wiring, the RETA-01 connects entirely through the drive’s internal backplane connector. There are no field terminals to wire, which significantly reduces installation time and eliminates potential wiring errors. However, the backplane connector pins must be inspected for corrosion or mechanical damage — particularly in drives that have been in service for more than ten years or installed in humid or chemically aggressive environments.

IP Address and Network Configuration: Once physically installed, the RETA-01 requires IP address assignment, subnet mask configuration, and gateway settings. These parameters are set via the drive’s control panel (such as the ACS-CP-C or ACS-CP-D control panel) or through DriveWindow software connected over a temporary serial link using an MFDT-01 flash memory tool or USB-to-serial adapter. Network administrators should pre-assign a static IP address and ensure the drive’s Ethernet port is registered in the plant network’s switch configuration before commissioning begins.

PLC Program and HMI Screen Adaptation: When migrating from a DDCS-based communication architecture to Ethernet, the PLC program must be updated to reflect the new communication path. Drive control words, status words, speed references, and fault codes are mapped differently over Modbus TCP compared to DDCS. The HMI screens — whether running on a Siemens TP700 Comfort Panel, an Allen-Bradley PanelView Plus, or a PC-based SCADA system — must be updated to read from the new Ethernet data addresses. This remapping work should be completed and tested in simulation before the physical cutover to minimize live system downtime.

Signal Isolation and Grounding: In retrofit scenarios where the drive cabinet shares a ground bus with older analog signal wiring, installing a signal isolator between the drive’s analog output and the PLC analog input card is recommended to prevent ground loop interference after the communication upgrade. This is particularly relevant when the RETA-01 is used alongside retained legacy wiring from the original DDCS installation.

Downtime Control During System Migration

Minimizing production downtime during a drive communication retrofit is a primary concern for plant managers and maintenance teams. The RETA-01 retrofit process, when properly planned, can typically be completed within a single planned maintenance window of four to eight hours — including physical installation, network configuration, PLC program update, HMI screen revision, and functional testing.

Pre-Staging: All configuration work that can be performed offline should be completed before the maintenance window begins. This includes preparing the updated PLC program with Ethernet-based drive communication blocks, configuring the RETA-01’s IP parameters in a bench test environment using a laptop and a small Ethernet switch, and verifying that the new communication addresses match the drive’s parameter set. Pre-staging eliminates the most time-consuming configuration steps from the live cutover window.

Program Backup: Before any hardware changes are made, a full backup of the existing PLC program, HMI project, and drive parameter set must be saved to a secure location. The drive parameter backup can be performed using the ACS-CP-C control panel’s parameter upload function or via DriveWindow. This backup serves as the recovery baseline if the cutover encounters unexpected issues and a rollback is required.

Parallel Testing: Where process conditions allow, the RETA-01 can be installed and configured while the drive continues to operate under its existing DDCS communication link. The new Ethernet communication path can be verified in read-only mode before the DDCS link is deactivated, confirming that drive status data is correctly received by the PLC over Ethernet before control authority is transferred.

Functional Verification: After cutover, the commissioning checklist should include verification of drive start/stop commands, speed reference tracking, fault acknowledgment, and status word readback over the new Ethernet link. Any discrepancies in control word bit mapping between the legacy DDCS configuration and the new Modbus TCP configuration must be resolved before the drive is returned to automatic control. NINERMAS supplies each RETA-01 unit pre-tested and verified against ABB factory specifications, with a 12-month warranty covering hardware defects identified after installation.

Retrofit Support FAQ

Q1: Is the RETA-01 a direct drop-in replacement for a failed unit in an existing ACS800 installation?
Yes. The RETA-01 is a direct replacement for existing RETA-01 units installed in ACS800 drives. The physical form factor, backplane connector, and firmware interface are identical. After physical replacement, the drive’s communication parameters (IP address, protocol selection, node address) must be re-entered via the control panel or DriveWindow, as these are stored in the module itself and are lost when the failed unit is removed.

Q2: Can the RETA-01 be used to replace a PROFIBUS adapter (RPBA-01) if we are migrating from PROFIBUS to Ethernet?
Yes, this is one of the most common retrofit scenarios. The RPBA-01 and RETA-01 occupy the same option slot form factor. After replacing the RPBA-01 with the RETA-01, the drive’s active fieldbus adapter parameter must be updated to select the Ethernet adapter, and the PLC program must be revised to use Modbus TCP or EtherNet/IP communication blocks in place of the PROFIBUS DP function blocks. HMI data source addresses will also require updating.

Q3: What pre-shipment testing does NINERMAS perform on the RETA-01?
Each RETA-01 unit supplied by NINERMAS undergoes functional verification prior to shipment, including power-on testing, communication port integrity check, and firmware version confirmation. Units are supplied with a 12-month warranty from the date of shipment. Customers requiring specific firmware versions or additional factory acceptance test documentation should contact NINERMAS at sale@ninermas.com before placing an order.

Q4: How quickly can NINERMAS supply the RETA-01 for an urgent breakdown situation?
NINERMAS maintains stock of the RETA-01 and other ABB ACS800 series option modules to support urgent breakdown and emergency spare requirements. Standard lead time for in-stock units is 3–7 business days for international shipments. For critical production line breakdowns, expedited shipping arrangements can be made. Contact the NINERMAS sales team at sale@ninermas.com or +0086 187 5021 5667 to confirm current stock availability and arrange priority dispatch.