Gold Whistle Servo Drive Complete Guide

Gold Whistle servo drive integration and troubleshooting

Introduction: Small size, high energy

Gold Whistle is an extremely high power density servo drive launched by Israeli company Elmo Motion Control. In a package of only 55 mm x 46 mm x 15 mm (approximately 38 cm ³), it can continuously output up to 1.6 kW of power (peak 3.2 kW) with an efficiency of over 99%. This driver adopts an onboard design (PCB soldering installation), which is very suitable for applications with strict requirements for volume and weight, such as robot joints, drones, precision machine tools, medical equipment, etc.

Gold Whistle supports multiple feedback sensors (incremental encoder, absolute serial encoder, Hall, rotary transformer, sine and cosine encoder), with communication options including USB, RS-232, CAN, and EtherCAT, and built-in safety torque cutoff (STO) functionality that complies with IEC 61800-5-2 SIL3 and ISO 13849-1 PL e. This article provides engineers with a systematic technical guide based on its installation guide, covering selection, power configuration, feedback connection, communication networking, heat dissipation design, and troubleshooting.

Product Model and Selection Points

2.1 Power level

Gold Whistle is divided into two voltage levels:

Voltage level, model series, continuous current (DC), peak current, maximum continuous power

100V series  1/100, 2.5/100, 5/100, 10/100, 15/100, 20/100 1 A, 2.5 A, 5 A, 10 A, 15 A, 20 A 2  × Ic 80 W ~ 1600 W

200 V series 3/200, 6/20, 9/200 3 A, 6 A, 9 A 2 × Ic 480 W, 960 W, 1450 W

Selection core: Select continuous current based on the rated current and peak demand of the motor. Note that "Amplitude sinusoidal/DC continuous current" in the table refers to the direct current value (used for trapezoidal waves or DC motors). If sine wave commutation is used, the effective value RMS=DC value/1.41. For example, the RMS continuous current of the 10/100 model is 10 A/1.41 ≈ 7.1 A.

Power supply voltage: 100V series main power supply range 12V-95V DC; The main power supply range of the 200 V series is from 12V to 195V DC (typical operating voltage is 170V). The control power supply (only required for the 200 V model) is 12V-95V DC, with a power consumption of ≤ 6 VA (including encoder power supply).

2.2 Part number identification

The part number label on the side of the drive contains complete model information, for example: GWH-20/100-EC represents 20 A continuous current, 100 V voltage level, EtherCAT communication version. When confirming the selection, it is necessary to check whether the voltage and current match the motor and power supply.

Power connection and configuration

3.1 100V series power supply solution

The 100V series can use a single power supply to simultaneously power the main power stage and control logic. There are two types of connection methods:

Internal VL+filtering (recommended): Connect the positive pole of the main power supply to VP+, and at the same time connect the VL+pin to VP+through the recommended filter (see Figure 9) to suppress power level noise interference in the control circuit.

External connection: Short circuit VP+and VL+directly (Figure 10). At this point, it is recommended to add a 100   nF~1   µ F ceramic capacitor near the driver.

If it is necessary to isolate the main power supply from the control power supply (for example, to improve anti-interference ability), diode coupling can be used (Figure 11): two independent isolated power supplies are used, connected to VP+and VL+through diodes, to ensure that the control power supply can still maintain logic when power is cut off.

3.2 200 V series dual power supply

The 200 V series must use two isolated power supplies:

Main power supply: 12V-195V connected to VP+/PR for motor drive.

Control power supply: 12V-95V connected to VL+/PR for logic and communication.

Important grounding rules (see Figure 3 and Figure 8):

PR (Power Return) must be connected to COMRET (Control Common Terminal) on the integrated board.

PE (protective grounding) must be externally connected to the chassis grounding (earth) and isolated from PR/COMNET (withstand voltage test requirements: 2 kV for 200 V models and 1.7 kV for 100 V models).

It is recommended to use twisted pair shielded wires for power cables, with the shielding layer grounded nearby on the power side.

3.3 Common Power Supply Malfunctions

Possible causes and solutions for the phenomenon

The driver cannot start, the indicator light is not on, and the control power supply is not connected or the voltage is too low. Measure the voltage between VL+and PR (should be 12V-95V)

Randomly restart the motor during operation and increase the VP+capacitor due to excessive fluctuations in the VP+power supply or high impedance in the PR circuit; Shorten PR routing and connect with a flat layer

Communication anomaly (EtherCAT/CAN): Control power supply noise interference and add LC filter at VL+; Check the single point connection between COMRET and PR

Feedback interface configuration

Gold Whistle offers three feedback ports (A, B, C) that support multiple sensor types. Port allocation depends on the model, please refer to the hardware manual for details.

4.1 Port A support

Incremental encoder: A, B, Z differential input (see Figure 12). Suitable for mainstream orthogonal encoders.

Hall sensor: Three single ended Hall signals (HA, HB, HC) used for initial commutation of brushless motors (Figure 13).

Absolute serial encoder: supports Endat 2.2, BiSS C/B, Panasonic, Tamagawa, Sanyo Denki, SSI. The clock and data are differential signals (Figure 14, 15). Pay attention to clock frequency and cable length when wiring.

Hiperface: requires a dedicated interface, at which point RS-232 is occupied (Figure 16).

4.2 Port B support

Incremental encoder (same as port A).

Sine/Cosine Encoder (Sin/Cos): 1 Vpp differential signal, capable of achieving high-resolution interpolation (Figure 18).

Rotary transformer: requires specific hardware options, excitation output, and sine/cosine feedback (Figure 19).

4.3 Port C - Simulated Encoder Output

Port C converts feedback signals from port A or B, or internal position/velocity variables, into differential incremental encoder outputs (A, B, Z signals). Can be used to transmit the driver position signal to the upper controller (Figure 20).

4.4 Feedback troubleshooting

Encoder communication error (absolute): Check if the clock frequency matches (Endat maximum 2 MHz, BiSS maximum 10 MHz); Measure differential voltage (usually 2-5 V); Ensure that the shielding layer is grounded at one end.

Hall signal incorrect: The motor cannot start smoothly and shakes. Use the Hall test function of EASII software to check the phase sequence and level of three signals.

Rotating transformer has no signal: check the excitation frequency (default 10   kHz) and amplitude; Measure the resistance of Sin/Cos to ground.

Communication interface and networking

5.1 USB 2.0

Used for debugging and configuration, connect to PC via Mini USB and use Elmo Application Studio (EASII) software. Note that the USB shielding layer must be connected to COMRET (Figure 24).

5.2 RS-232 TTL level

Standard asynchronous serial communication, with a logic level of 3.3V TTL, cannot be directly connected to the PC's RS-232 (requires an external level conversion chip, see Figure 23). Suitable for simple point-to-point communication.

5.3 CAN bus

Supports CAN 2.0B with a maximum baud rate of 1 Mbps. Both ends of the network must be connected to a 120 Ω terminal resistor (Figure 26). CAN-H and CAN_L are twisted pair cables. Common faults: No communication on the bus → Check for terminal resistance, node address conflicts, and common mode voltage exceeding the range (CAN-H/L ground voltage should be around 2-3 V).

5.4 EtherCAT / Ethernet

Gold Whistle can serve as an EtherCAT slave with IN and OUT ports, and supports LED status indication (RUN, ERR, LINK/ACT, SPEED). The EtherCAT-IN port can also be configured as a regular Ethernet (requiring corresponding firmware support). When connecting, use a standard CAT5e or higher Ethernet cable, and be careful not to form a loop between the two ports (Figure 25).

Troubleshooting: EtherCAT scan cannot reach slave station → Check IN/OUT wiring direction; Confirm the slave address (configured through EASII or SDO); Observe the status of the RUN LED (green flashing indicates PRE-OP, green constant light indicates OP). If the ERR LED lights up, it indicates a synchronization error or watchdog timeout, and the main station cycle and DC synchronization settings need to be checked.

Safety Function: STO (Safe Torque Off)

Gold Whistle has built-in dual channel STO inputs (STO1 and STO2) that comply with IEC 61800-5-2 SIL3 and ISO 13849-1 PL e/Cat. 3. When any channel is disconnected or the signals of two channels are inconsistent, the driver immediately cuts off the motor power output (no torque state).

6.1 Wiring (TTL mode)

STO1 and STO2 are 3.3V logic inputs and can accept signals ranging from 3.3V to 5V. Two normally open contacts of the safety relay need to be connected, or the 24V output of the safety PLC (requires external level conversion). Figure 29 shows the TTL connection method. STO-RET is the common return terminal (should be connected to COMRET).

6.2 Common STO Issues

Drive unable to enable (Status LED orange): STO not released. Measure the STO-RET voltage of STO1 and STO2, which should be at a high level (>2V). If it is a low level, check if the safety circuit is closed.

Unable to recover after STO triggering: The safety channel may malfunction (such as two channels with inconsistent levels for more than 1 second). The 24V safety power supply needs to be cut off and reconnected. If it repeatedly occurs, check if the safety relay contacts are stuck.

Key points of PCB integration and layout

7.1 Welding and Mechanical Installation

Gold Whistle is designed to be directly soldered onto PCBs. Pin spacing of 1.27mm (J2) and 2mm (power end). Before welding, ensure that the PCB pads are flat to avoid virtual soldering. You can also use a socket, but it is not recommended as it will increase inductance and reduce heat dissipation performance.

There are four screw mounting holes at the bottom of the heat sink, which can fix the drive to the metal chassis to assist in heat dissipation. If relying solely on air convection, it is necessary to ensure a minimum gap of 10mm above and below the radiator.

7.2 Partition Layout Principles (Figure 4)

The PCB should be divided into two areas:

Power zone: including VP+, PR, PE, VL+, and motor output lines. These lines should be as wide and short as possible to avoid crossing with control signals.

Control and communication area: including feedback, I/O, USB, RS-232, EtherCAT, CAN, etc. These signals should be kept away from the power line and provide a complete reference plane on the ground plane.

7.3 Grounding and Return

PR (Power Return): It is the current circuit for the main power supply and motor, and must use a low impedance plane, preferably a complete ground plane layer.

COMRET (Control Common Terminal): Connect all low-level references of control signals. COMRET must be connected to PR at a single point on the integrated board (see Figure 3).

PE (protective grounding): connected to the casing and safety ground. There must be no connection between PE and PR on the PCB (voltage isolation). PE wiring only conducts electricity during abnormal faults.

Grounding error case: Connecting COMRET directly to PE resulted in a control circuit grounding loop, causing noise false triggering. The correct approach is to connect COMRET to PR, and then connect PR to PE through a high resistance resistor (such as 1   M Ω) and a parallel capacitor (such as 10   nF). However, according to safety regulations, PE and PR should be directly connected externally. In fact, Figure 3 shows that PE is externally connected to the ground, and PR is directly connected to the PE bypass? More accurate: Insulation must be maintained between PR and PE, and only a capacitor (Y capacitor) is connected between the ground and PR on the power supply side. It is recommended to strictly follow the grounding topology in the hardware manual.

Heat dissipation design

8.1 Thermal data

The thermal resistance (from the radiator to the environment) is approximately 10 ° C/W.

The thermal time constant is about 240 seconds (reaching 2/3 of the final temperature rise in 4 minutes).

Shutdown temperature: The radiator temperature is between 86 ° C and 88 ° C.

8.2 Do you need an external radiator?

Use the provided power consumption chart (Chapter 11) to evaluate:

Set the maximum radiator temperature to 80 ° C.

Measure the maximum ambient temperature (e.g. 40 ° C), allowing a temperature rise of Δ T=40 ° C.

Find the power consumption Pd (W) based on the working voltage and output current curve.

If Pd ≤ 4   W, no additional heat sink is required (relying solely on natural convection). If Pd>4   W, a heat sink needs to be installed (Elmo provides model WHI-HEAT-SINK-2).

Engineering experience: Actual testing shows that typical power consumption is 30% to 50% lower than the theoretical value in the chart, so the margin can be appropriately relaxed. But in a sealed case, the ambient temperature may be much higher than 40 ° C, so it must be measured.

Common fault codes and troubleshooting (based on EASII software)

Types of faults, possible causes, and solutions

Main power supply undervoltage VP+voltage below 12V, check power output; Increase capacitor holding voltage

Check if the main power supply is stable when the overvoltage VP+exceeds the upper limit (95V or 195V); Is there regenerative energy to lift the busbar

Overcurrent (instantaneous) motor short circuit, phase to phase short circuit, Hall commutation error, disconnect the motor, and measure the motor winding resistance with a multimeter; Reset and change phase angle

Overcurrent (effective value): Excessive load and steep acceleration/deceleration increase the acceleration/deceleration time; Reduce load; Choose a higher current model

Overheating (radiator) with insufficient heat dissipation and high ambient temperature, installing radiator/fan; Clean up dust; Reduce current limit

Encoder fault signal loss, CRC error check cable connection; Reduce communication speed; Replace the encoder

STO triggers the safety circuit to disconnect and reset the safety relay; Check the integrity of STO signal

Bus communication timeout (EtherCAT) synchronization loss, network cable disconnection check network topology; Increase watchdog time; Restart the main station

Debugging and software tools

Elmo Application Studio (EASII) is the official configuration, debugging, and diagnostic tool. After connecting via USB or RS-232, you can:

Automatically identify drive model and firmware version.

Motor parameter configuration (select motor type, number of poles, encoder resolution).

Autotune the current loop, speed loop, and position loop.

A real-time oscilloscope (Scope) collects waveforms such as current, velocity, position, and tracking error.

Fault history and export.

Initialization steps:

Hardware installation and power on.

Run EASII and connect to the drive.

Execute 'New Project', select motor model or manually input parameters.

Perform 'current loop self-tuning' (measure motor resistance and inductance).

Perform 'speed loop self-tuning' (automatically optimize PI parameters).

Save parameters to non-volatile memory.

Tip: When encountering difficult faults, using EASII's "recorder" function to capture data from the first few seconds of the fault can effectively locate occasional issues.