A range of NEMA 23 stepper motors with integrally mounted micro-stepping drives and a choice of on-board controls is available from Mclennan Servo Supplies. The Applied Motion Products' STM series is available in two lengths with stall-torque ratings of 88 and 148Ncm from a 12-to-70V DC supply. The drive and control housing is rear-mounted and includes all interfacing power and signal connections. The stepper motors share a configuration and programming capability with all of the company's ST series stand-alone intelligent stepper drives, which are available for torques up to 13Nm and bus voltages to 320V DC. The motors' power stage is protected and features selectable micro-stepping resolutions up to 51200steps/rev, with advanced 20kHz PWM current control, automatic anti-resonance waveform damping and torque-ripple smoothing. There are two levels of control that both offer three digital inputs, one digital output and one analogue input. The STM-S version handles step and direction, CW/CCW pulse, A/B quadrature encoder following and a basic level of host control using the company's SCL programming language. All configuration data is held in flash memory. The advanced STM-Q controller version uses the high-level Q programming language to write sequences of complex multi-tasked motion and machine control with full electronic gearbox, maths and registration functions. Q programmer software is also supplied free for creation and editing of stand-alone programs. When fitted with the rear-mounted encoder option, the motor may be programmed through the Q version to provide basic stall detection or a more advanced stall-prevention measure that monitors motor-command position to encoder lag and will finish its move under stall conditions. Configuration and program data is saved in flash and EEPROM.
