Siemens 6SN1121-0BA11-0AA1 600 V DC Closed Loop Control Module

The Siemens 6SN1121-0BA11-0AA1 is a plug-in closed-loop control module for the SIMODRIVE 611-A drive system, configured for main spindle drives using 1PH asynchronous motors in the universal analog HSA configuration. This module installs into the SIMODRIVE 611-A power module chassis and manages closed-loop speed and torque regulation for the spindle axis via analog setpoint interface. Compatible CNC platforms include SINUMERIK 840C, 840D, 810D, and earlier Siemens control generations built around the 611-A drive family.

Siemens discontinued this part number in September 2018, making surplus stock the primary source for facilities maintaining installed SIMODRIVE 611-A spindle systems. The unit ships in its original Siemens cardboard box. Version C is marked on the module label; the box carries Version D with a separate serial number (T-M12035527 on box, T-K22024418 on module label), indicating the module and packaging were separately serialized. Both are included. The module shows no visible signs of installation or damage. Buyers should confirm version and firmware compatibility with their existing 611-A drive chassis and SINUMERIK control revision prior to installation.