
B–63523EN–1/03
7. FEEDRATE CONTROL/ACCELERATION
AND DECELERATION CONTROL
825
(3)The acceleration/deceleration change time is constant. If deceleration
becomes necessary during acceleration, an acceleration/deceleration
change occurs for the constant time specified in parameter No. 8416.
This means that the acceleration/deceleration change rate is no longer
constant. (With conventional look–ahead bell–shaped acceleration/
deceleration before interpolation, the acceleration/deceleration
change rate is constant.)
Feedrate
Time t
time 2t
Time
This bell–shaped
acceleration/deceleration
Conventional bell–shaped
acceleration/deceleration
t: Bell–shaped time constant
To distinguish between conventional look–ahead bell–shaped
acceleration/deceleration before interpolation and this look–ahead
bell–shaped acceleration/deceleration before interpolation, the former is
referred to as bell–shaped acceleration/deceleration with constant
acceleration/deceleration rate type, and the latter is referred as
bell–shaped acceleration/deceleration of constant acceleration/
deceleration change time type.
To enable look–ahead bell–shaped acceleration/deceleration before
interpolation (of constant acceleration/deceleration change time type), set
the parameter as follows:
Bit 3 (SBL) of parameter No. 1603 to 1
For a bell–shaped time constant, parameter No. 8416 as used for the
conventional bell–shaped time constant can be used. However, the valid
data range is extended to 400 ms.