Siemens SINUMERIK 840C - Manual (Page 235)

6 NC Machine Data (NC MD), NC Setting Data (NC SD) 09.95
6.4 Axis-specific MD 1 (axial data 1)
MD 276* is calculated as follows:
Maximum speed [rev/min] . 360 degrees/input resolution
MD 276* = ––––––––––––––––––––––––––––––––––––––––––––––––––
60 x run-up time [sec] . 10000
Example:
Maximum speed: 1000 rev/min
Measured value: 200 msec
Reserve: 100 msec
C axis input resolution: 0.01 degrees
2000 rev. . 360 degrees . 100
MD 276* = –––––––––––––––––––––––––––– = 400 [ units IS . 10000 / s 2 ]
60 sec. . 0.3 sec . 100
Maximum speed with G00 280*
Default value Lower input limit Upper input limit Units
10 000 +0 99 999 999 1 000 units/min (IS)
Active on
NC Stop
NC MD 280* is used to define the maximum speed to which the axis can accelerate (rapid
traverse limit). If rapid traverse G00 has been programmed, the axis traverses at this speed.
All speeds programmed or input relate to this speed.
The maximum permissible speed depends on the position control resolution, the input
resolution and the interpolation time (refer to Section entitled ”Axis (Analog) and Spindle
Installation”).
Ref. point cutoff speed 284*
Default value Lower input limit Upper input limit Units
300 +0 99 999 999 1 000 units/min (IS)
Active for all
channels of
mode group
in STOP
MD 284* is accepted when all channels of the mode group are in STOP and applies
from the next reference point approach.
During approach to the reference point, the cutoff speed takes effect as soon as the reducing
cam is reached, i.e. the "Deceleration" signal is active (see NC MD 244*). In the case of
distance coding, the whole referencing procedure is carried out with this speed. The feedrate
override switch is not taken into account, except in the first position (0 %). The specified cutoff
speed must not exceed the maximum speed (NC MD 280*). (For a detailed description of
reference point approach see also Section entitled ”Axis (Analog) and Spindle Installation”).
With reference point control with "distance coded reference marks", the reference point creep
velocity must not exceed a maximum value. See Section entitled ”Axis (Analog) and Spindle
Installation” for a calculation.
Recommended value:
A reasonable upper limiting value would be 1 m/min, but values between 100 and 500 mm/min,
depending on the K
V
factor, would be preferable.
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SINUMERIK 840C (IA)