ZD-MXXP-485 Stepper Motor Driver

Control NEMA stepper motor drivers with RS485.

Register and functions designed for ZD-M42P-485 or ZD-M57P-485 NEMA stepper motor back-mounted drivers controller via RS485 such as CAN總線步進馬達驅動器控制器RS485接口42/57型微小型驅動控制器 or 57 integrated stepper motor driver module controller with cooling shell 485CAN pulse control mode .

Main contribution is c libraries zdmxxp.c and zdmxxp.h.

Features

• Control stepper motor motion

  • homing
  • goto_position
  • move_forwards
  • move_backwards
  • stop

• Read limit switch states

  • read_button_states reads home, limit_down and limit_up switch states and returns their states (1 or 0)

• Read motor state

  • REG_CURRENT_POS_H - Current position
  • REG_TARGET_POS_H - Target position currently moving towards
  • REG_CURRENT_STATE - Reads current state, which may be STATE_UNDEFINED, STATE_IDLE, STATE_ACCEL, STATE_CONST, STATE_DECCEL, STATE_HOMING, STATE_ERROR_RETURNING, STATE_UP_BUTTON_PRESSED, STATE_DOWN_BUTTON_PRESSED

• Read and write register values (the meanings of these registers are my own intepretation based on their Chinese terms)

  • REG_ADDRESS - Device address
  • REG_MICROSTEP - 1 / 2 / 4 / 8 / 16 / 32 (and more depending on driver)
  • REG_LOCK_MODE - Whether device locks itself from moving when not in motion
  • REG_ACC_STEP_H - Stepper acceleration steps
  • REG_ACC_PARAM_H - Stepper acceleration parameter
  • REG_INIT_PERIOD - Period of stepper clocks when accelerating
  • REG_MAX_PERIOD - Period of stepper clocks when at constant (aka max) speed
  • REG_MAX_DIST_H - Maximum steps that can be travelled by stepper
  • REG_ZERO_POS_H - Home position wrt to zero
  • REG_LIM_SW_OFST - Offset between home limit switch and designated home position

• Theoretically this implementation should be cross-platform between linux and windows. libmodbus is cross platform - the only linux-only dependency used by me is sleep - of which should be easily substituted for windows.

Sources

The core modbus libraries are forked from libmodbus. Register information is obtained and translated from this product page. I found that this guide was supremely helpful for me in using libmodbus.

Usage and demo

1. Clone repo
2. Run test_rtu with command ./test_rtu. This is a demo program. You can specify COM port with ./test_rtu /dev/ttyUSB1. You can change default value in zdxxmp.h.
3. To include this in your own projects, all dependencies are included in src folder.

Build

To build, G++ (and Gcc) is required. Makefile so just run terminal command make in ./ZD-MXXP-485-Stepper-Motor-Driver/src