Rexroth DM Series Servo Drives

Technical Dossier

Product Details And Specifications

Rexroth DM Series: Comprehensive Module Range and Technical Overview

The Bosch Rexroth DM Series represents a family of compact, high-performance servo drives deployed extensively across global heavy industry sectors including petrochemical refining, nuclear power generation, offshore platforms, and continuous-process manufacturing. Engineered to interface with Rexroth SERCOS and analog command architectures, DM Series drives are embedded in legacy motion control systems that remain operational well beyond their original design lifecycle. Their installed base spans facilities in Europe, North America, and Asia-Pacific, where replacement cycles are driven by mean-time-between-failure (MTBF) data rather than planned obsolescence schedules. The DM-51 in particular is a single-axis digital servo amplifier rated for brushless AC servo motor control, commonly paired with Rexroth MKD and MHD motor families.

The Evolution of DM Series Architecture

The Rexroth DM Series was introduced as part of the DIAX02 and DIAX03 drive platform generations, succeeding earlier analog servo amplifier families. Early DM variants operated on ±10V analog command interfaces with resolver feedback. Subsequent revisions integrated SERCOS I fiber-optic communication, enabling deterministic real-time motion coordination across multi-axis CNC and robotics installations. The DM-51 belongs to the mid-generation DIAX03 platform, characterized by its modular power section, onboard parameter memory (E²PROM), and compatibility with Rexroth IndraControl L and V controller families. As the platform matured, Rexroth transitioned customers toward the IndraDrive C (HCS) and IndraDrive M (HMS/HMD) families, which offer EtherCAT and PROFINET connectivity. However, DM Series drives remain in active service in facilities where full drive-train replacement is cost-prohibitive, making long-term spare parts availability a critical operational requirement. Firmware compatibility between DM generations requires careful cross-referencing of parameter sets (P-0-xxxx) to avoid axis tuning regression during unit substitution.

DM Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified models within the Rexroth DM Series drive family, organized by functional classification:

Single-Axis Servo Amplifiers (Compact Class)

• DM-51: Single-axis digital servo amplifier, DIAX03 platform, ±10V / SERCOS interface, for MKD/MHD motors.
• DM-51.1: Revised DM-51 with enhanced EMC filtering and updated firmware revision level.
• DM-51.2: DM-51 variant with extended ambient temperature rating for harsh environment enclosures.
• DM-52: Higher continuous current rating variant of DM-51, suited for larger MHD motor frames.
• DM-52.1: DM-52 with integrated brake chopper circuit for vertical axis applications.

Dual-Axis and Multi-Axis Configurations

• DM-53: Dual-axis servo amplifier sharing DC bus, reduces cabinet footprint in multi-axis gantry systems.
• DM-53.1: DM-53 with SERCOS II interface upgrade, backward compatible with DIAX03 controllers.
• DM-54: High-power dual-axis unit, rated for servo motors up to 22 kW continuous shaft power.

Power Supply and Bus Modules

• DM-PS-01: Dedicated DC bus power supply module for DM Series drive lines, 400V AC input.
• DM-PS-02: Regenerative power supply variant, feeds braking energy back to AC mains.
• DM-BM-01: Bus module for parallel DC bus distribution across multiple DM drive units.

Feedback and Communication Modules

• DM-FB-01: Resolver feedback interface module, plug-in card for DM-51/52 base units.
• DM-FB-02: EnDat 2.1 encoder feedback interface, enables absolute position retention on power cycle.
• DM-SC-01: SERCOS I fiber-optic communication card for DM Series amplifiers.
• DM-SC-02: SERCOS II interface card, supports higher baud rate ring topologies up to 16 Mbit/s.
• DM-AN-01: Analog command interface card, ±10V input with 16-bit resolution DAC.

Sourcing Hard-to-Find & Obsolete DM Series Parts

The Rexroth DM Series has been classified as a mature/end-of-life product line by Bosch Rexroth. OEM new stock is no longer available through standard distribution channels. DriveKNMS maintains a dedicated inventory of tested surplus, refurbished, and new-old-stock (NOS) DM Series units sourced through authorized industrial liquidation and decommissioning programs. For facilities operating DM-51 and related modules in long-term maintenance contracts, DriveKNMS provides lifecycle extension support including: unit-level repair with original Rexroth replacement components, firmware re-flashing to the last stable revision, parameter backup and restoration services, and cross-reference mapping to IndraDrive C equivalents for customers planning phased migration. All units are held in ESD-safe, climate-controlled storage and shipped with full test documentation. Lead times for common models such as DM-51 and DM-52 are typically 3–7 business days from confirmed order.

Quality Control for the DM Series Range

Each DM Series unit processed by DriveKNMS undergoes a structured multi-stage verification protocol designed specifically for the DIAX03 drive platform architecture. Stage 1 — Visual and Mechanical Inspection: examination of power terminals, fiber-optic ports, plug-in card connectors, and capacitor condition. Stage 2 — DC Bus Energization: controlled ramp-up via variac to rated DC bus voltage (560–650 VDC for 400V class units) with leakage current monitoring. Stage 3 — Functional Drive Test: the unit is connected to a matched Rexroth MKD or MHD test motor and commanded through full velocity and torque loop operation via SERCOS or analog interface. Stage 4 — Thermal Soak: continuous operation at 80% rated current for 2 hours with thermal imaging to identify failing IGBTs or gate driver degradation. Stage 5 — Parameter Verification: all factory default parameters are confirmed against the Rexroth DM Series parameter reference manual. Units that pass all five stages are issued a DriveKNMS test certificate with date stamp, technician ID, and measured performance data.