46 Operation Theorycoordinate system? If the resolution of external encoder is 10,000pulses per 1mm and the motor will move 1mm if the motion con-troller send 1,000 pulses, It means that when we want to move 1mm, we need to send 1,000 pulses to motor driver then we will getthe encoder feedback value of 10,000 pulses. If we want to use anabsolute command to move a motor to 10,000 pulses position andcurrent position read from encoder is 3500 pulses, how manypulses will it send to motor driver? The answer is (10000 – 3500 ) /(10,000 / 1,000)=650 pulses. The motion controller will calculate itautomatically if users set “move ratio” already. The “move ratio”means the (feedback resolution/command resolution).4.2.2 Absolute and Relative Position MoveIn the coordinate system, we have two kinds command for usersto locate the target position. One is absolute and the other is rela-tive. Absolute command means that user give the motion control-ler a position, then the motion controller will move a motor to thatposition from current position. Relative command means that usergive the motion controller a distance, then the motion controllerwill move motor by the distance from current position. During themovement, users can specify the speed profile. It means user candefine how fast and at what speed to reach the position.
