The OMS Motion OMD17B is a compact bipolar chopper stepper motor drive designed for direct back-mounting on NEMA 17 frame motors. Its 42.3 mm square footprint matches the motor faceplate, creating an integrated motor-drive package without additional panel space. The drive operates from an 8-35 VDC supply and delivers up to 1.7 A peak per phase, supporting 4-, 6-, and 8-lead bipolar stepper motors.

How is step resolution configured?

A 3-position DIP switch (S1) selects the microstepping resolution: full-step (200 steps/rev), 1/2 (400), 1/4 (800), 1/8 (1,600), or 1/16 (3,200 steps/rev with a standard 1.8° motor). The drive automatically detects and selects the appropriate current decay mode during operation. A through-hole resistor socket (J4) sets the phase current proportionally, with values from 3.3 kΩ (0.29 A) to 68 kΩ (1.59 A).

How are the control signals interfaced?

STEP, DIR, and ENABLE inputs are optically isolated and require an external high-level voltage reference (VIN+, 5-20 VDC) applied to J3 pin 1. The STEP input triggers on every rising edge with a minimum pulse width of 1 µs, supporting step frequencies up to 500 kHz. ENABLE is internally pulled high if left floating, defaulting the drive to enabled for simple pulse/direction control with minimal wiring. Screw-terminal connectors on all interfaces simplify field installation.