Product Specification Document: 6SN1118-1NK01-0AA1

6SN1118-1NK01-0AA1 is a dual-axis closed-loop control loop board belonging to Siemens SIMODRIVE 611 U HR drive system platform, designed as resolver feedback control unit rather than standalone power output hardware, matched to work in tandem with SIMODRIVE 611 power modules to realize full servo closed-loop motion control. It supports resolver signal acquisition for two servo axes simultaneously, delivering speed, torque and position closed-loop regulation with integrated speed/torque setpoint interface, and allows functional expansion via optional accessory boards. This unit is a core control spare part for traditional CNC machine tool and automation production line retrofits and maintenance; original mass production has been terminated, and it is only supplied as after-sales spare inventory worldwide. The unified plain ordering code for warehouse and ERP recording is 6SN11181NK010AA1.

Manufacturer Brand: Siemens AG, GermanyFull Model Part Number: 6SN1118-1NK01-0AA1Unpunctuated Order Code: 6SN11181NK010AA1Product Series: SIMODRIVE 611 U HRProduct Category: Dual-axis resolver closed-loop control loop boardFeedback Interface Standard: Resolver dedicated signal inputAxis Capacity: 2 independent servo axes per unitLifecycle Status: Officially cancelled since April 1, 2015, available only as maintenance spare partsCertifications: CE compliant, conforming to EU industrial EMC and low voltage safety directivesNet Weight: Approximately 0.6 kg per unitMounting Form: Vertical plug-in installation inside SIMODRIVE 611 drive rack cabinetHousing Structure: Metal shielding casing for anti-interference performance in workshop environments

This control board undertakes full closed-loop algorithm operation for two resolver-equipped synchronous servo motors. It receives resolver position and speed feedback signals in real time, executes position loop, speed loop and current loop PID calculation, and outputs adjusted drive reference signals to paired SIMODRIVE 611 power modules to drive servo motor operation. Three switchable control modes are supported: position control for precise positioning tasks, speed control for constant rotation scenarios, and torque control for tensioning, pressing and constant force processing applications. The built-in speed/torque setpoint channel accepts analog reference commands from CNC main controller or upper PLC system, with expandable signal terminals via optional plug-in modules to add digital I/O, encoder auxiliary feedback or communication interfaces. It is specially optimized for resolver-equipped motors widely used on old-generation machining centers, lathes, grinders and textile machinery, providing stable motion control without relying on expensive high-resolution optical encoders. As a mature discontinued spare component, it mainly serves equipment maintenance, old machine overhaul and production line renovation projects globally, compatible with standard Siemens 802D, 810D and 840D CNC host systems.

Feedback Signal Input: Dedicated resolver excitation and sampling circuit for dual axes, standard industrial resolver impedance matchingControl Mode Switching: Position, speed, torque three closed-loop modes configurable via parameter settingSpeed Regulation Ratio: Up to 1:10000 steady speed adjustment range with low steady-state speed errorPosition Loop Response: Fast dynamic loop bandwidth optimized for medium and low inertia servo loadsReference Signal Interface: Analog 0–10 V speed/torque setpoint input, compatible with CNC standard command signal levelsDigital I/O Circuit: DC 24 V compatible PNP/NPN universal digital input and output terminals for enable, fault reset and status feedback signalsInternal Power Supply: Powered by SIMODRIVE 611 rack internal bus power, no separate external power wiring requiredProtection Logic: Integrated over-speed monitoring, resolver signal loss detection, axis overload pre-alarm and short-circuit interlock protection logicOperating Ambient Temperature: Stable rated operation range 0 °C to 40 °C inside sealed drive cabinetStorage Temperature Range: -40 °C to 70 °C for long-term warehouse stocking and transportationHumidity Resistance: Max 95% relative humidity non-condensing environment allowed during operationElectromagnetic Compatibility: Metal shield housing and internal filter circuits to suppress workshop frequency converter and power grid interferenceFirmware Compatibility: Matches SIMODRIVE 611 drive firmware version 8.3 and above for full feature unlocking

Primary Matching Power Hardware: Full range of SIMODRIVE 611 power modules including single-axis and dual-axis power output units that fit 611 standard rackUpper Control Host: Siemens 802D, 810D, 840D CNC numerical control systems; SIMATIC S7 series PLC via PROFIBUS DP communicationServo Motor Types: Siemens 1FT5, 1FT6, 1FK6 synchronous servo motors equipped with resolver feedback devicesExpansion Optional Boards: Plug-in option modules for extra digital I/O, incremental encoder secondary feedback and PROFIBUS DP communication expansionInstallation Infrastructure: Standard SIMODRIVE 611 U rack mounting chassis, rack backplane bus connectors, shielding ground busbarsProgramming and Debug Tools: Siemens SimoCom U drive parameter configuration software, PC adapter cable for drive parameter upload/downloadOfficial Documentation: SIMODRIVE 611 system hardware manual, resolver axis parameter adjustment guide, fault diagnosis troubleshooting manualReplacement Alternative Unit: 6SN1118-1NK01-0AA2 as upgraded successor model for new replacement installations

Main Deployed Equipment: CNC vertical machining centers, horizontal lathes, surface grinders, internal and external cylindrical grinders, metal cutting machine tools with resolver servo configurationKey Industrial Sectors: Precision metal machining, automotive component processing, mold manufacturing, textile spinning and weaving equipment, printing and packaging automated machinery, woodworking CNC production linesEnvironmental Adaptability: Designed for indoor factory workshop installation, suitable for general machining workshop dust and vibration levels with standard cabinet ventilationDeployment Restrictions: Cannot operate independently; must be plugged into complete SIMODRIVE 611 rack with feeding module and power modules to form a full drive system; incompatible with Sinamics S120 and other later-generation Siemens drive platformsApplication Limitation: Optimized exclusively for resolver feedback motors; not suitable for direct drive with EnDat, SSI or pure TTL incremental encoder motors without resolver conversion adapters

Before plugging the control board into the 611 rack, fully cut off the rack three-phase AC input power to avoid bus voltage surge damaging circuit components. Align the board backplane connector accurately with the rack bus slot and lock the side fixing screws to guarantee reliable electrical contact and vibration resistance during machine operation. After physical installation, use SimoCom U software to upload axis parameter files matching the connected resolver servo motor; incorrect resolver pole pair parameter settings will cause positioning deviation or motor overheating. All analog signal wiring between CNC controller and control loop board must adopt shielded twisted cable, with shielding layer single-point grounded at the cabinet grounding bar to eliminate signal drift and noise interference. Regular drive firmware updates for the SIMODRIVE rack do not erase saved axis parameters stored on this control board module. In case of board fault, direct replacement with the successor 6SN1118-1NK01-0AA2 is allowed with minor parameter recalibration; cross-model replacement without parameter adjustment will trigger axis fault codes. Routine machine maintenance such as cabinet fan cleaning, dust removal and power cycle operation will not affect long-term control loop stability. Since original production stopped, spare unit storage requires dry constant-temperature warehouse conditions to prevent circuit board aging and solder joint oxidation.