Trapezoidal Acceleration/Deceleration - Fuji Electric micrex-sx SPH User Manual

7-3 Functions of Pulse Generation Mode

7-3-4 Trapezoidal acceleration/deceleration

• This module (NP1F-MP1/NP1F-MP2) executes the processing for trapezoidal acceleration/deceleration using the
acceleration/deceleration register.
25MHz
• When automatic acceleration/deceleration is enabled (by the control register), the 20-bit-length up/down counter
operates as follows. (For details, refer to the paragraph for control register in Section 6.)
• Before the deceleration point is detected
Target frequency register > Current frequency register = = > Count up (acceleration)
Target frequency register < Current frequency register = = > Count down (deceleration)
Target frequency register = Current frequency register = = > Hold (constant speed)
• After the deceleration point is detected
Base frequency register > Current frequency register = = > Count up (acceleration)
Base frequency register < Current frequency register = = > Count down (deceleration)
Base frequency register = Current frequency register = = > Hold (constant speed)
• The time until maximum output frequency is reached since the pulse output has been stopped (0Hz) is calculated
by the following formula. (Setting range of acceleration/deceleration register: 1 to 65535)
• When the frequency register is of 16-bit length
Acceleration/deceleration time (ms) = 65,535 / {25,000kHz / (Set value of acceleration/deceleration register + 1)}
In this case, the minimum time until maximum output frequency is reached since the pulse output has been
stopped is:
Acceleration/deceleration time = 65,535 / 25,000kHz / 2 = 5.2ms
• When the frequency register is of 20-bit length
Acceleration/deceleration time (ms) = 1,048,575 / {25,000kHz / (Acceleration/deceleration register + 1)}
In this case, the minimum time until maximum output frequency is reached since the pulse output has been
stopped is:
Acceleration/deceleration time = 1,048,575 / 25,000kHz / 2 = 84ms
Acceleration/
deceleration
register
2
1 / n
20-bit up/down counter
(Current frequency)
Compare
Target frequency
7-8
Decelerate
Constant speed
Accelerate