Product Description:

The DMA 085B 9101-D is a servo drive module produced by Bosch Rexroth Indramat within the DMA Servo Drive Modules series. As a three-phase power stage for synchronous and asynchronous motors, the unit supplies regulated current to match commanded torque and velocity profiles in automated machinery. Integrated axis positioning capability lets machine controllers assign it to standalone positioning tasks without extra motion cards. In multi-axis systems, the module occupies a 100 mm bay on the common backplane and relies on shared cooling air moved by cabinet fans.

During operation, a dedicated 24 V supply delivers 1.35 A to the control electronics, while the main DC link stabilizes at 670 VDC / 715 VDC to feed the output stages. Command and diagnostic data are exchanged over the CANopen/CANrho interface, allowing direct integration with Indramat motion controllers. At 4 kHz switching frequency, the module can furnish a peak current of 86 Arms in open-loop mode and a closed-loop rating of 47 Arms. At 8 kHz, the corresponding limits are 63 Arms and 31 Arms. These current ranges set the available torque before the drive saturates. Two integrated backplane fans draw air through the heat sink, and the airflow pattern supports continuous operation without external chillers. The standard encoder interface and 12-bit resolver channel provide feedback compatibility for most Rexroth motors.

Thermal margins change above 45 °C, so output capability decreases by 1.25 A/K at 4 kHz and by 0.95 A/K for 8 kHz switching. When temperature derating is applied, the closed-loop continuous current of 31 Arms at 8 kHz becomes the principal sizing value for high-speed applications that run in warmer enclosures. Air drawn from the backplane passes directly across the power semiconductors, so the cooling path remains effective as cabinet temperatures fluctuate. This arrangement reduces thermal stress on the power section during sustained operation.