STEPPERONLINE DM320T User Manual

Introduction

The DM320T is a digital stepper drive with a simple design and easy setup. Utilizing advanced stepper control technology, this drive powers 2-phase and 4-phase stepper motors smoothly, offering optimal torque with low motor heating and noise. Its operating voltage range is 10-30VDC, and it can output up to 2.2A current. Microstepping and output current settings are configured via DIP switches, making the DM320T an ideal choice for applications requiring simple step & direction control of NEMA11, 14, 16, and 17 stepper motors.

Features

• Anti-Resonance for optimal torque, smooth motion, low motor heating, and reduced noise.
• Motor auto-identification and parameter auto-configuration for optimal torque from various motors.
• Step & direction (PUL/DIR) control.
• Multi-Stepping for smooth motor movement.
• Optically isolated inputs.
• Input voltage: 10-30VDC.
• 8 selectable micro-step resolutions (400-12800 steps/rev) via DIP switches.
• 8 selectable output current settings (0.3A – 2.2A) via DIP switches.
• Soft-start feature prevents motor "jump" on power-up.
• Pulse input frequency up to 60 KHz.
• Automatic idle-current reduction.
• Protections for over-voltage and over-current.

Applications

The DM320T stepper drive is designed for 2-phase (1.8°) or 4-phase (0.9°) NEMA11, 14, 16, 17 hybrid stepper motors. It is suitable for various industries including CNC, medical, automation, and packaging. Applications include X-Y tables, engraving machines, labeling machines, mills, plasma cutters, laser cutters, and pick-and-place devices. Its performance, simple design, and ease of setup make it ideal for many step & direction control applications.

Specifications

Electrical Specifications

Environment

Mechanical Specifications

The mechanical specifications are detailed in Figure 1. The drive has overall dimensions of 86mm x 79mm. Mounting holes are provided for installation. The unit has a height of 27.5mm and a bracket depth of 11.5mm. Side mounting is recommended for better heat dissipation.

Elimination of Heat

The DM320T drive's reliable working temperature should be kept below 60°C (140°F). To maximize heat sink area, it is recommended to mount the drive vertically. Forced cooling methods may be used if necessary.

Connection Pin Assignments and LED Indication

The DM320T features two connector blocks: P1 for control signals and P2 for power and motor connections. Detailed descriptions are provided in sections 4, 5, and 9.

Connector P1 Configurations

⚠ Notice: (1) Shielding control signal wires is suggested. (2) To avoid interference, do not tie PUL/DIR control signals and motor wires together.

Connector P2 Configurations

⚠ Warning: Do not plug or unplug the P1 & P2 terminal blocks while the DM320T is powered on to avoid drive damage or injury.

LED Light Indication

The DM320T has two LEDs: GREEN is the power indicator (always on). RED is the protection indicator, which flashes 1-2 times every 3 seconds when a protection is enabled. The number of flashes indicates the specific protection type (refer to section 11 for details).

Control Signal Connector (P1) Interface

The DM320T accepts differential and single-ended inputs (including open-collector and NPN output). It features 3 optically isolated logic inputs on connector P1 for line drive control signals, minimizing electrical noise. Using line drive signals is recommended for enhanced noise immunity in interference-prone environments.

Connections to Open-Collector Signal (Common-Anode)

This diagram shows the connection of the DM320T driver to a controller using open-collector output signals. The controller's VCC, PUL, DIR, and ENA signals are connected via series resistors (R) and opto-couplers to the DM320T's P1 pins (PUL, DIR, ENA). The required resistor values are R=0 for VCC=5V, R=1K for VCC=12V, and R=2K for VCC=24V. The DM320T's P1 connector also includes OPTO, VDC (10-30VDC), and GND terminals. The P2 connector is used for motor connections (A+, A-, B+, B-).

Connections to Differential Control Signal

This diagram illustrates connections for differential control signals. The controller provides differential signals (PUL+, PUL-, DIR+, DIR-, ENA+, ENA-) which are connected via series resistors (R) and opto-couplers to the DM320T's P1 pins (PUL, DIR, ENA). The same resistor value notes apply. The DM320T's P1 connector also has OPTO, VDC, and GND terminals. The P2 connector is for motor connections (A+, A-, B+, B-).

Motor Connection

The DM320T can drive 2-phase and 4-phase bipolar hybrid stepper motors with 4, 6, or 8 wires.

Connections of 4-lead Motor

4-lead motors are the most flexible and easiest to connect. Motor speed-torque performance depends on winding inductance. The drive's output current should be multiplied by 1.4 to determine the peak output current for the specified phase current.

Figure 4: 4-lead Motor Connections: This diagram shows a 4-lead stepper motor connected to the DM320T's P2 connector. The motor's two windings are connected to terminals A+ and A-, and B+ and B-.

Connections of 6-lead Motor

Similar to 8-lead motors, 6-lead motors offer two configurations for high speed or high torque operations. The higher speed configuration, known as half coil, uses one half of the motor's inductor windings, resulting in lower inductance and thus lower torque output. The higher torque configuration, or full coil, uses the full coil windings.

Half Coil Configuration

The half coil configuration uses 50% of the motor phase windings, providing lower inductance and lower torque output. Torque output is more stable at higher speeds. This configuration is also referred to as half chopper. To set the drive output current, multiply the specified per-phase (or unipolar) current rating by 1.4 to determine the peak output current.

Figure 5: 6-lead motor half coil (higher speed) connections: This diagram illustrates a 6-lead stepper motor connected in a half-coil configuration to the P2 terminals. One end of each coil (A+, A-) and (B+, B-) are connected to the driver. The center taps of the coils are connected to NC (No Connection) terminals on the driver.

Full Coil Configuration

The full coil configuration for a six-lead motor is suitable for applications requiring higher torque at lower speeds. This is also known as full copper. In full coil mode, motors should be run at only 70% of their rated current to prevent overheating.

Figure 6: 6-lead motor full coil (higher torque) connections: This diagram shows a 6-lead stepper motor connected in a full-coil configuration to the P2 terminals. Both ends of each coil are connected to the driver (e.g., A+, A-, B+, B-). The center taps are connected to NC terminals.

Connections of 8-lead Motor

8-lead motors offer high flexibility, allowing connection in series or parallel to suit a wide range of applications.

Series Connection

A series motor configuration is typically used for applications requiring higher torque at lower speeds. Due to higher inductance, performance may degrade at higher speeds. In series mode, motors should be run at only 70% of their rated current to prevent overheating.

Figure 7: 8-lead motor series connections: This diagram depicts an 8-lead stepper motor connected in series to the P2 terminals. The connections are made to utilize the motor's windings in series for higher torque at lower speeds.

Parallel Connection

An 8-lead motor in a parallel configuration offers more stable torque at lower speeds but lower torque overall. Due to lower inductance, it provides higher torque at higher speeds. To determine peak output current, multiply the phase (or unipolar) current rating by 1.96, or the bipolar current rating by 1.4.

Figure 8: 8-lead motor parallel connections: This diagram shows an 8-lead stepper motor connected in parallel to the P2 terminals. The connections are made to utilize the motor's windings in parallel for higher torque at higher speeds.

Power Supply Selection

The DM320T can power medium and small-sized stepper motors (NEMA11 to NEMA17 frame sizes). Proper selection of supply voltage and output current is crucial for good driving performance. Supply voltage primarily affects high-speed performance, while output current determines motor torque, especially at lower speeds. Higher supply voltage allows higher motor speeds but may increase noise and heating. For low-speed requirements, a lower supply voltage is preferable to reduce noise, heating, and improve reliability.

Regulated or Unregulated Power Supply

Both regulated and unregulated power supplies can be used. Unregulated supplies are preferred for their ability to handle current surges and respond quickly to current changes. If a regulated supply is chosen, it should be specifically designed for stepper/servo controls. If only standard switching power supplies are available, use "OVERSIZE" high current output rating supplies (e.g., a 4A supply for a 3A motor) to prevent issues like current clamp. For unregulated supplies, a lower current rating (typically 50%-70% of motor current) can be used because the drive draws current from the supply's capacitor only during the PWM cycle's ON duration, resulting in lower average current draw.

Power Supply Sharing

Multiple DM320T drives can share a single power supply to reduce costs, provided the supply has sufficient capacity. To prevent cross-interference, connect each stepper drive directly to the shared power supply separately. Avoid daisy-chaining power supply input pins.

Selecting Supply Voltage

The DM320T operates within a 10-30VDC input range. When selecting a power supply, consider power line voltage fluctuations and back EMF generated during motor deceleration. A 24VDC output voltage is ideally suggested to allow for these variations. Higher supply voltage can increase motor torque at higher speeds, helping to prevent step loss. However, it may also cause increased motor vibration at lower speeds, over-voltage protection, or drive damage. Therefore, choose a supply voltage that is sufficiently high for the intended application.

DIP Switch Configurations

This drive uses a 6-bit DIP switch to configure microstep resolution and motor operating current.

Microstep Resolution Configurations

Microstep resolution is set by DIP switches SW4, SW5, and SW6. The table below shows the settings for different microstep resolutions (for a 1.8° motor):

Current Configurations

Higher drive current generally results in more motor torque but also increased heating in the motor and drive. Output current should be set to prevent motor overheating during prolonged operation. Motor coil connections (parallel/series) significantly affect inductance and resistance, making it important to set drive output current based on motor phase current, leads, and connection methods. The motor manufacturer's phase current rating is a key factor, but selection also depends on leads and connections.

Dynamic Current Configurations

The first three bits (SW1, SW2, SW3) of the DIP switch set the dynamic current. Select a setting closest to your motor's required current:

Note: Due to motor inductance, the actual current in the coil may be lower than the dynamic current setting, especially at high speeds.

Standstill Current Configuration

The standstill current is automatically set to 50% of the selected output current. This reduction occurs 0.4 seconds after the last pulse.

Automatic Motor Matching & Self Configuration

Upon power-up, the DM320T automatically configures itself with the best settings to match the driven stepper motor for optimal performance. No manual action is required.

Wiring Notes

• To improve anti-interference performance, use twisted pair shielded cable.
• To prevent noise interference with PUL/DIR signals, keep pulse/direction signal wires separate from motor wires by at least 10 cm. Otherwise, motor-generated signals can disturb pulse direction signals, leading to motor position errors, system instability, or failures.
• If a single power supply serves multiple DM320T drives, connect each drive directly to the power supply separately, rather than daisy-chaining.
• Do not plug or unplug connector P2 while the drive is powered ON. High current flows through motor coils even at standstill, and pulling or plugging P2 with power on can cause a high back-EMF voltage surge, potentially damaging the drive.

Typical Connection

A complete stepping system includes a stepping motor, stepping drive, power supply, and controller (pulse generator). A typical connection is illustrated in Figure 9.

Figure 9: Typical connection: This diagram outlines a complete stepping system. It shows a controller (pulse generator) sending control signals (PUL, DIR, ENA) to the DM320T stepper drive. The DM320T is then connected to a stepping motor and a 10-30VDC power supply.

Sequence Chart of Control Signals

To avoid fault operations and deviations, PUL, DIR, and ENA signals must adhere to specific timing rules, as shown in the following diagram.

Figure 10: Sequence chart of control signals: This timing diagram illustrates the required sequence and timing for the PUL, DIR, and ENA control signals. It shows that ENA should be ahead of DIR by at least 5µs (t1), DIR should be ahead of PUL by 5µs (t2), PUL pulse width should be at least 7.5µs (t3), and the low level width of PUL/DIR should be at least 7.5µs (t4).

Remarks:

• t1: ENA must be ahead of DIR by at least 5µs. Typically, ENA+ and ENA- are NC (not connected). Refer to "Connector P1 Configurations" for more details.
• t2: DIR must be ahead of PUL effective edge by 5µs to ensure correct direction.
• t3: Pulse width must not be less than 7.5µs.
• t4: Low level width must not be less than 7.5µs.

Protection Functions

To enhance reliability, the drive incorporates built-in protection features. The RED LED indicates protection status:

When protections are active, the motor shaft will be free, or the red LED will blink. Reset the drive by repowering it after removing the cause of the problem.

Troubleshooting

If the drive operates improperly, the first step is to identify whether the problem is electrical or mechanical. Next, isolate the component causing the issue. This may involve disconnecting individual components to verify their independent operation. Documenting each troubleshooting step is important for future reference and for assisting technical support.

Many motion control system problems stem from electrical noise, controller software errors, or wiring mistakes.

Problem Symptoms and Possible Causes