Fine Positioning Needed in Telescope Mount


Optical Tube Assembly

Optical Tube Assembly (OTA)

The BSC Industries team in MA partnered with a custom astronomical instrumentation and control systems manufacturer to develop a direct drive telescope mount system to be used for astronomical and space situational awareness (SSA) applications.

The application involved an optical tube assembly (OTA) for a 0.8m optical telescope, which is a typical payload for the telescope mount which uses direct drive motors.

The BSC Industries team recommended the Copley Controls Accelnet Plus 2-Axis Panel EtherCAT BE2 for the application. Features of the digital servo drive include:


Accelenet Plus Servo Drive

  • Control Modes: Cyclic Synchronous Position-Velocity-Torque (CSP, CSV, CST), Profile Position-Velocity-Torque, Interpolated Position, Homing, Camming, Gearing, Indexer
  • Command Interface: CAN open application protocol over EtherCAT (CoE); ASCII and discrete I/O; Stepper commands; ±10V position/velocity/torque
  • Communications: EtherCAT; RS-232
  • Feedback: Incremental Encoders – Digital quad A /B; Analog Sin/Cos; Panasonic Incremental A Format;  Aux. quad A /B encoder / encoder out; Absolute Encoders – SSI, EnDat, Absolute A, Tamagawa & Panasonic Absolute A Sanyo Denki Absolute A , BiSS (B & C)
  • I/O Digital: 8 High-speed inputs; 2 Motor over-temp inputs; 8 Opto-Isolated inputs; 5 Opto-Isolated outputs; 2 Opto-Isolated brake outputs
  • Analog: 2 Reference Inputs, 12-bit

Direct Drive Telescope Mount prototype

The drive has the ability to utilize the system’s extremely high resolution (27 Bit) EnDat Absolute encoder for ultra-fine positioning. Test results including the drive addition to the application showed positive returns in helping the system avoid resonance points (natural frequencies) in the testbed – a big win for our customer.

When you have an out-of-this-world custom project, turn to BSC Industries for high-quality products and a partner that can provide custom solutions. Contact us with your questions or to request a quote.