Automatic Deceleration Point Calculation - Fuji Electric micrex-sx SPH User Manual

7-3 Functions of Pulse Generation Mode

7-3-5 Automatic deceleration point calculation

• When automatic deceleration point calculation is enabled, this module (NP1F-MP1/NP1F-MP2) automatically
calculates the deceleration point.
Accelerating
Decelerating
Command pulse
• When automatic deceleration point calculation is enabled, the deceleration point register is cleared to zero when
pulse output is stopped.
• After command pulse output is started, the command pulse register is counted up during acceleration, and
counted down during deceleration.
In the above figure, in sections A and C, the command pulse register is counted up, and counted down in section
B. While pulses are being output under frequency command 3, the value of the deceleration point register
becomes D=A-B+C.
The command pulse register is counted down according to the command pulse.
Comparing the command pulse register (the remaining number of output pulses) with the deceleration point
register, operation is decelerated from the point at which the following relationship holds true:
Deceleration point register > Command pulse register
Precautions:
· When acceleration is constant, the deceleration point is automatically calculated.
· If any of 1) base frequency register, 2) acceleration/deceleration register 1, 3) speed multiplication register and
4) deceleration point register are updated, except maximum frequency register, during pulse output, the
deceleration point is not detected.
· When acceleration/deceleration is disabled, even if automatic deceleration point calculation is enabled, the
deceleration point register is forcibly cleared to zero. As a result, "Command pulse register > Deceleration point
register" always holds true during pulse output, and deceleration is not performed.
· If the number of pulses output after phase-Z (interrupt signal) has been detected is too small in interrupt mode,
the target frequency may not be reached. (Speed is limited to a level from which operation can be decelerated
and stopped by the set number of pulses.)
Deceleration point
register 32-bit up/down
counter
Comparator
Command pulse
register 32-bit
Down counter
Frequency 1
Frequency 2
A B
Deceleration point signal
Deceleration start
Frequency 3
C D
7-10
Time