NPM PPCI7443, Руководство пользователя

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Operation Theorem
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41
MaxVel = accel*Tacc;
StrVel = decel *Tdec;
where accel/decel represents the acceleration/deceleration rate in unit of
pps/sec^2. The area inside the trapezoidal profile represents the moving
distance.
The unit of velocity setting is pulses per second (PPS). Usually, the unit of
velocity in the manual of motor or driver is in rounds per minute (rpm). A
simple conversion is necessary to match between these two units. Here we
use a example to illustrate the conversion.
For example:
A servomotor with a AB phase encoder is used in a X-Y table. The
resolution of encoder is 2000 counts per phase. The maximum
rotating speed of motor is designed to be 3600 rpm. What is the
maximum pulse command output frequency that you have to set on
PPCI7443?
Answer:
MaxVel = 3600/60*2000*4
= 48000pps
The reason why *4 is because there are four states per AB phase (See
Figures in Section 4.4).
Usually, the axes need to set the move ratio if their mechanical resolution is
different from the resolution of command pulse. For example, if an
incremental type encoder is mounted on the working table to measure the
actual position of moving part. A servomotor is used to drive the moving
part through a gear mechanism. The gear mechanism is used to convert the
rotating motion of motor into linear motion.(see the following diagram). If the
resolution of motor is 8000 pulses/round. The resolution of gear mechanism
is 100 mm/round.(i.e., part moves 100 mm if motor turns one round). Then
the resolution of command pulse will be 80 pulses/mm. If the resolution of
encoder mounting on the table is 200 pulses/mm, then users have to set the
move ratio as 200/80=2.5 by the function:
_7443_set_move_ratio (axis, 2.5);
Moving part
Motor
Gear
Encoder
Table