3.4.2Motor Timing

Refer to the time chart in Figure 3-7when designing the control circuit or software for starting and stopping the motor. Also, note the following precautions:

Precautions for Designing the Motor Control Circuit and Software

(1)Stop step

z To stop the motor, excite for 10 msec with the same phase as the last one in the printing step.

(2)Pause state

z In the pause state, do not excite the step motor by having I0, I1 go high so as to prevent the motor from heating. Even when the step motor is not excited, it maintains force to prevent the paper from sliding by a torque operation.

(3)Start step

z To restart the motor from the stop step, immediately shift the motor into the print sequence.

z To restart the motor from the pause (no excitation) state, shift the motor into the print step sequence after outputting the same phase as that of the stop step for the first step time of the acceleration step.

Input signals for a sample drive circuit are shown in Figure 3-7.

H

PH1

L

H

PH2

L

H

I0,I1

L

Print step

Pause

 

Pause

 

Start

Print step

 

step

 

standby

 

step

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3-7 Motor Start/Stop Timing

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