Micro-stepping divides a stepper motor step into many smaller parts, producing a smoother and less noisy motor rotation. Stepper motors can have a jerky motion and produce much noise at lower speeds, micro-stepping can smooth out this jerkiness and quiet down the noise.

The CMD-4EX-SA-TBD and CMD-2ED-SA has 8 micro-stepping resolutions, as outlined in the table below. Even while the motor is in motion, the micro-stepping resolution can be changed. The CMD-4ED and CMD-2ED firmwares adds the MSR command to simplify the setting of the micro-stepping resolution to a single command. The CMD-4CR and CMD-2CR firmware can adjust the resolution by setting IO30, IO31, and IO32, as shown in the chart below.


MSR

Setting

IO30

IO31

IO32

0

Full Step

0

0

0

1

1/2 step

1

0

0

2

1/4 step

0

1

0

3

1/8 step

1

1

0

4

1/16 step

0

0

1

5

1/32 step

1

0

1

6

1/64 step

0

1

1

7

1/128 step

1

1

1


The number of micro-steps per revolution is calculated by the following equation: "DEGREE" is the full step angle of the motor, and "USTEP" is the micro-stepping resolution.


µstep revolution = 360 / (DEGREE * USTEP)


For example, using a 1.8° motor and a micro-stepping resolution of 1/8, the number of micro-steps/revolution would be [360° / (1.8° * 1/8)] = 1600