Siemens SINUMERIK 840C User Manual
Page 265
6 NC Machine Data (NC MD), NC Setting Data (NC SD)
09.95
6.5 Spindle-specific MD (spindle data)
Acceleration time constant
with position controller gears 1-8
478*-485*
Default value
Lower input limit
Upper input limit
2 000
0
50 000
1 ms
Active on
Power On
Assignments
Gear
1
2
3
4
5
6
7
8
NC MD
478*
479*
480*
481*
482*
483*
484*
485*
The control issues the ramp-form setpoints for acceleration and braking operations (ramp
function generator). The gradient of this ramp is determined by the acceleration time constant.
Notes
•
Two acceleration time constants are provided for each gear ratio:
–
Acceleration time constant without position controller
(MD 419* to 426*)
–
Acceleration time constant with position controller
(MD 478* to 485*)
The time constants without position controller are used for the open-loop control mode, the
time constants with position controller for the position mode.
•
MD 478* to 485* must be set such that the motor can follow the specified setpoints at any
one time without reaching the current limit. Particular care should be taken be taken that
this is also the case in the field weakening range.
•
The data in 478* to 485* should always be greater than the data in 419* to 426*.
•
You can set MD 419* to 426* so that the motor is accelerated to the current limit for a
certain time. If a ramp-up generator is built into the actuator, you can set MD 419* to 426*
to 0. In this case, the setpoint changes in steps on acceleration and deceleration.
Calculation of the permissible acceleration in position controlled spindle operation.
Development of spindle speed in controlled mode at the acceleration limit (M3/M4)
Speed
Maximum speed for position control mode
Time
T
6–80
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Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)