Genicom MatrixPrinter LA36 - Manual (Page 115)

5-28
The MPU receives phase excitation data for the stepping motor and sends data to turn the motor drive HIC on or
off. Data is set to high for a phase to be excited. Motor rotation is controlled by sequentially changing the
excitation of the four phases.
Slew control is applied when motor rotation starts or stops:
Start: Gradual acceleration. The excitation period gradually is made shorter.
Stop: Gradual deceleration. The excitation period gradually is made longer.
The motor drive HIC outputs constant current power based on the motor drive mode (idle, low and high speed).
To give a correct torque to the motor in each drive mode, the MPU outputs drive current control signals SPI1
and SPI2 to the motor drive HIC.
Phase switching is controlled by the timer in the MPU (Figure 5.26).
A
D
AB
B
BC C CD
DA
Figure 5.26 Phase switching and carriage drive direction