ACS Motion Control SP+ Series Modules: SP+SAR-LT-4E

Technical Dossier

Product Details And Specifications

ACS Motion Control SP+ Series: Comprehensive Module Range and Technical Overview

The ACS Motion Control SP+ series represents a high-density, multi-axis motion controller platform deployed across global heavy industry sectors including petrochemical processing plants, semiconductor fabrication facilities, nuclear research installations, and precision machine tool manufacturing. The SP+ architecture is built around a modular, scalable backplane that supports simultaneous multi-axis coordinated motion, real-time EtherCAT communication, and deterministic trajectory generation. Its installed base spans thousands of systems across North America, Europe, and Asia-Pacific, making it one of the most widely referenced platforms in the industrial automation spare parts market.

The Evolution of SP+ Architecture

ACS Motion Control introduced the SP+ platform as the successor to its earlier SPiiPlus family, consolidating motion, I/O, and communication functions into a unified, EtherCAT-native controller architecture. Early SP+ variants relied on proprietary SERCOS and analog ±10V drive interfaces. Subsequent generations integrated native EtherCAT master capability, enabling direct connection to third-party servo drives without intermediate gateways. The SAR sub-series (Stand-Alone with Real-time expansion) introduced dedicated real-time Ethernet ports and expanded axis counts per node, addressing the demand for tighter synchronization in multi-robot and gantry applications. The LT designation within the SAR line indicates a compact form-factor variant optimized for space-constrained cabinet installations while retaining full software compatibility with the broader SP+ ecosystem. Compatibility across SP+ generations is maintained at the software level through ACS's ACSPL+ programming environment and the SPiiPlus MMI Application Studio, ensuring that programs written for earlier SP+ nodes can be migrated to current hardware with minimal modification. Legacy variants using older firmware branches (pre-v2.x) may require firmware upgrade procedures before integration with modern EtherCAT topologies.

SP+ Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced models within the ACS SP+ and SPiiPlus platform family. Models are classified by functional category.

Stand-Alone Real-Time Controllers (SAR Series)

• SP+SAR-LT-4E: Compact 4-axis EtherCAT stand-alone real-time motion controller, LT form factor
• SP+SAR-LT-8E: Compact 8-axis EtherCAT stand-alone real-time controller, LT cabinet-mount variant
• SP+SAR-4E: Standard 4-axis EtherCAT stand-alone real-time motion controller, full form factor
• SP+SAR-8E: Standard 8-axis EtherCAT stand-alone real-time controller, full form factor
• SP+SAR-16E: 16-axis EtherCAT stand-alone real-time controller for high-axis-count systems

Modular Expansion Controllers (UDMnt / UDMsd Series)

• UDMnt-4: 4-axis universal drive interface module, NT backplane mount, ±10V analog output
• UDMnt-8: 8-axis universal drive interface module, NT backplane mount
• UDMsd-4: 4-axis universal drive interface module, SD compact form factor
• UDMsd-8: 8-axis universal drive interface module, SD compact form factor

I/O Expansion Modules

• SP+IO-16DI: 16-channel digital input expansion module for SP+ backplane
• SP+IO-16DO: 16-channel digital output expansion module, 24VDC sourcing
• SP+IO-8AI: 8-channel analog input module, 16-bit resolution, ±10V range
• SP+IO-8AO: 8-channel analog output module, 16-bit resolution, ±10V range

Communication & Network Adapters

• SP+ECAT-MASTER: Dedicated EtherCAT master communication adapter for SP+ platform integration
• SP+PROFIBUS-DP: PROFIBUS-DP slave adapter module for SP+ series network connectivity
• SP+ETHERNETIP: EtherNet/IP adapter enabling SP+ integration into Rockwell/Allen-Bradley networks

Power Supply Modules

• SP+PSU-24V: 24VDC regulated power supply module for SP+ backplane and I/O bus

Sourcing Hard-to-Find & Obsolete SP+ Parts

Several SP+ and SPiiPlus variants have reached end-of-sale status as ACS Motion Control has transitioned its product roadmap toward the EtherCAT-native SPiiPlusSC and CDHD2 drive platforms. DriveKNMS maintains a dedicated inventory of discontinued SP+ modules, including early SAR variants, legacy UDMnt axis modules, and first-generation I/O expansion cards. For end-users operating SP+-based systems in long-lifecycle environments — including nuclear instrumentation, aerospace test rigs, and continuous-process chemical plants — DriveKNMS provides lifecycle extension support through verified refurbished units, functional equivalents, and cross-reference sourcing. All obsolete units are sourced from decommissioned OEM systems or authorized surplus channels and are subject to full functional validation before dispatch. Customers requiring long-term supply agreements for SP+ spare parts are encouraged to contact DriveKNMS to discuss consignment stocking and priority allocation programs.

Quality Control for the SP+ Range

The SP+ platform's multi-layer architecture — combining real-time DSP processing, EtherCAT ASIC communication, and high-density I/O backplane interfaces — requires a structured, multi-stage test protocol to validate module integrity before redeployment. DriveKNMS applies the following procedures to all SP+ units processed through its facility:

• Visual and mechanical inspection: Examination of backplane connectors, capacitor condition, and PCB surface for corrosion, burn marks, or mechanical damage consistent with overcurrent or ESD events.
• Power-on functional test: Modules are powered within a controlled SP+ test rack. Boot sequence, firmware version reporting, and LED status indicators are verified against ACS factory specifications.
• EtherCAT communication validation: Each EtherCAT-capable module is connected to a reference EtherCAT master and verified for correct ESM state machine transitions (INIT → PRE-OP → SAFE-OP → OP) and PDO mapping integrity.
• Axis output verification: For controller modules, all axis command outputs (analog ±10V or EtherCAT cyclic PDO) are verified under simulated load conditions using calibrated measurement equipment.
• I/O channel functional test: All digital and analog I/O channels are individually stimulated and read-back verified to confirm channel isolation and signal accuracy within published tolerance bands.
• Burn-in cycle: Units are operated continuously for a minimum of 24 hours under representative load conditions to screen for latent component failures prior to shipment.