Indramat R91120116 RD500 Vector Drive Controller Unit

Module Feature

R91120116 is a Bosch Rexroth Indramat RD500 digital drive controller, belonging to the RD52 vector control variant. It executes field-oriented closed-loop vector control for asynchronous spindle motors, supporting constant power spindle operation, C-axis positioning and speed regulation. It works with matched RD power supply / power stage modules to form a complete spindle drive group. Control interfaces include analog ±10V speed setpoint, discrete I/O and optional SERCOS digital motion bus. Parameter and firmware data are stored on removable memory module for quick replacement and commissioning. Integrated protection covers overcurrent, motor overtemperature, encoder fault, mains monitoring and communication timeout. Cabinet convection / forced air cooling design, IP20 construction. Widely deployed on CNC turning, milling and grinding machine main spindle systems.

Working principle

The controller receives speed or position setpoints from CNC via analog or SERCOS interface. It calculates three-phase current reference values for the power stage using vector algorithm. Current and position feedback signals from motor sensors are continuously sampled for closed-loop regulation. It generates enable, fault and status signals to the host CNC system. Braking energy handling is coordinated with the shared DC bus infeed unit.

Onboard components

Main DSP control PCB, current loop ASIC, SERCOS / analog interface circuit, encoder evaluation board, digital input/output terminal block, parameter memory module, status signal circuit, front service connector.

LED indicators

Front panel LEDs for power ready, enable active, fault and communication status; detailed fault codes and drive parameters are read via Rexroth IndraWorks commissioning software.

Hardware self‑diagnosis

Power-on self-test detects encoder signal loss, motor over-temperature, phase current imbalance, control supply undervoltage, memory module missing and communication failure. Fault history and parameter logs are stored locally.

Programming software

Commissioning, auto-tuning, parameter backup and diagnostics use Rexroth IndraWorks software.

Electrical & Process Parameters

Model:R91120116 Brand:Bosch Rexroth Indramat Series:RD500 RD52 Device type:Vector Drive Controller Control supply:24V DC Main circuit voltage:3AC 380~480V Control modes:Vector control, V/F, C-axis positioning Communication:Analog ±10V, SERCOS, digital I/O Cooling:Cabinet air cooling Protection:IP20 Function:Closed-loop speed and position control for asynchronous spindle motors

Mechanical & Structure

Mounting:Cabinet rack mounting Protection class:IP20 Housing:Metal control card assembly

Environmental

Operating temperature:0℃ ~ +40℃ (derate above 40℃) Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:CE compliant Status:Indramat original RD500 spindle drive spare

Installation

Install controller inside control cabinet and pair with compatible RD power stage. Wire 24V control supply, motor feedback cable, command signal and I/O wiring. Load motor parameters and perform current loop auto-tune in IndraWorks. Verify spindle ramp, C-axis positioning and emergency stop functions before production test.

Interface

DC bus control connector, encoder feedback port, analog setpoint terminal, SERCOS bus connector, digital I/O terminal, 24V control power terminal.

Diagnostic

Speed oscillation: Incorrect loop gain tuning, encoder noise or mechanical resonance. F2xx encoder fault: Encoder cable damage, connector loose or encoder hardware failure. Overcurrent trip: Motor winding insulation fault, power stage defect or mechanical jam. SERCOS communication loss: Bus termination error, cable break or address conflict.

Product Brief

Bosch Rexroth Indramat R91120116 RD500 vector spindle drive controller, supports field-oriented control and C-axis positioning, analog and SERCOS interfaces, designed for CNC machine tool asynchronous spindle motor control.