EM-318A is a bipolar chopper-type microstepping stepper motor controller designed for precise and efficient motion control. The bipolar operation ensures optimal torque for most stepper motors, while microstepping enables smooth, low-noise operation especially at low speeds.
The controller supports seven stepping resolutions from full step up to 1/64 microstepping, allowing flexible optimization between torque, resolution and speed for various applications.
The integrated auxiliary oscillator enables standalone operation with preset speeds. These speeds can be activated using four digital inputs.
The oscillator includes an adjustable acceleration ramp, allowing smooth transitions between speeds and reliable startup even at higher frequencies without loss of steps.
The built-in indexing function allows execution of predefined motion sequences. Each sequence defines:
Sequences can be triggered via four digital inputs, enabling repeatable motion control without external logic.
All controller parameters are configured digitally using the EM-236 Interface Unit. This enables fast setup and easy duplication of settings across multiple devices.
| Operating voltage | 12–35 VDC |
| Idle current | Approx. 20 mA |
| Current setting range | 0.1 – 3 A (step 0.1 A) |
| Auxiliary oscillator | 50 – 10 000 Hz |
| Frequency accuracy | typ. 0.5% |
| Ramp adjustment | 0.1 – 5 s (0 → 10 000 Hz) |
| Max step frequency | 15 kHz |
| Analog input (Ain) | 0–10 V (pulse frequency 0–10 kHz) |
| Control input level | "ON" = 4–30 V / "OFF" = 0–1 V or open |
| RS-485 | Half-duplex, 9600 / 19200 baud (Modbus RTU) |
| Operating temperature | 0 … +50 °C |
| Dimensions | 87 × 72.5 × 25 mm |
| Weight | 100 g |