Duo Whistle

Super Compact 2 axis Servo package


Integrated Dual Whistle Solution:

The power of two Whistle servos drives in a single board solution

Elmo’s Duo is an integrated solution for X, Y applications. Highly compact, it combines two Whistle servo drives in one package and operates using a single DC power supply.

The Duo is offered as two different models to provide maximum DC voltage of either 60 or 100 V. Both models support up to 15 amps continuous current.

The Duo can operate in current, velocity, position and advanced position modes with permanent-magnet synchronous brushless motors, DC brush motors, linear motors or voice coils. The solution is designed for use with any type of sinusoidal and trapezoidal commutation with vector control.

As with other Elmo SimplIQ digital products, the Duo can be easily set up and tuned using Elmo’s Composer software tools.

Current Control
  • Fully digital

  • Sinusoidal commutation with vector control or trapezoidal
    commutation with encoder and/or digital Hall sensors

  • 12-bit current loop resolution

  • Automatic gain scheduling, to compensate for
    variations in the DC bus power supply

Velocity Control
  • Fully digital

  • Programmable PI and FFW (feed forward) control filters

  • Sample rate two times current loop sample time

  • "On-the-fly" gain scheduling

  • Automatic, manual and advanced manual tuning
    and determination of optimal gain and phase margins

Position Control
  • Programmable PIP control filter

  • Programmable notch and low-pass filters

  • Position follower mode for monitoring the motion of the slave
    axis relative to a master axis, via an auxiliary encoder input

  • Pulse-and-direction inputs

  • Sample rate four times current loop sample time

  • Fast event capturing inputs

Advanced Position Control (in Advanced model only)
  • Position-based and time-based ECAM mode that supports
    a non-linear follower mode, in which the motor tracks the
    master motion using an ECAM table stored in flash memory

  • PT and PVT motion modes

  • Dual (position/velocity) loop

  • Fast output compare (OC)

Communication Options
  • RS-232 serial communication

  • CANopen for fast communication in a
    multi-axis distributed environment

Feedback Options
  • Incremental Encoder - up to 20 Mega-Counts
    (5 Mega-Pulse) per second

  • Digital Halls - up to 2 KHz

  • Incremental Encoder with Digital Halls for
    commutation - up to 20 Mega-Counts per second for encoder

  • Interpolated Analog Sine/Cosine Encoder -
    up to 250 KHz (analog signal)
    • Internal Interpolation - up to x4096

    • Automatic Correction of amplitude mismatch, phase mismatch,
      signals offset

    • Auxiliary emulated, unbuffered, single-ended, encoder output

  • Resolver
    • Programmable 10~15 bit resolution

    • Up to 512 Revolution Per Second (RPS)

    • Auxiliary emulated, unbuffered, single-ended, encoder output

  • Tachometer, Potentiometer

  • Elmo drives provide supply voltage for all the feedback options

Fault Protection
  • Software error handling

  • Status reporting for a large number of possible fault conditions

  • Protection against conditions such as excessive temperature,
    under/over voltage, loss of commutation signal, short circuits
    between the motor power outputs and between each
    output and power input return

  • Recovery from loss of commutation signals
    and from communication errors


150 x 25.4 x 105 mm (5.90" x 1.00" x 4.13")
CANopen interface (DS 301, DS 402)
Current mode
Velocity mode, follower
Position jog, follower, point-to-point
Pulse and direction input
Dual loop, velocity and position
PT position versus time mode
PVT position and velocity versus time
ECAM / Follower
Overall user program size
2 KB
32 KB