Siemens SINUMERIK FM-NC Installation And Startup Manual page 143

03.96
Note
These MD are not required to match the encoder, but they must be entered
correctly for setpoint calculation. The load revolutions are entered in
MD 31050: DRIVE_AX_RATIO_DENOM and the motor revolutions in
MD 31060: DRIVE_AX_RATIO_NUMERA.
Example A of
Spindle with signal generator (500 pulses) mounted directly on spindle. Internal
multiple = 2048. Internal calculation resolution = 1000 increments per degree.
encoder matching
Internal resolution =
Internal resolution =
The encoder increment corresponds to 0.3515 internal increments. An encoder
increment corresponds to 0.003515 degrees (highest possible positioning
resolution).
Example B of
Spindle with rotary encoder on motor (2048 pulses), internal multiple = 2048, 2
encoder matching gear stages:
Gear stage 1: Motor/spindle = 2.5/1
Gear stage 2: Motor/spindle = 1/1
Gear stage 1
Internal
resolution
Internal
resolution
One encoder increment corresponds to 0.034332 internal increments. An
encoder increment corresponds to 0.000034332 degrees (highest possible
positioning resolution).
Gear stage 2
Internal
resolution
Internal
resolution
One encoder increment corresponds to 0.08583 internal increments. One
encoder increment corresponds to 0.00008583 degrees (highest possible
positioning resolution).
 Siemens AG 2000 All Rights Reserved
SINUMERIK 840D Installation and Start-Up Guide (IAD) – 04.00 Edition
6 Assigning Parameters to the Control and the PLC Program
360 degrees
MD 31020 * 2048
360 * 1 * 1000
500 * 2048 *1
360 degrees MD 31080
=
*
MD 31020 * 2048 MD 31070
360 degrees 1
=
* *
2048 * 2048 pulses 1
360 degrees MD 31080
=
*
MD 31020 * 2048 MD 31070
360 degrees 1
=
* *
2048 * 2048 pulses
1
6.9 Axes and spindles
MD 31080
* 1000
*
MD 31070
0.3515
MD 31050
* 1000 incr/degr.
*
MD 31060
1
* 1000 pulses/degree = 0.034332
2,5
MD 31050
* 1000 incr/degr.
*
MD 31060
1
* 1000 pulses/degree = 0.08583
1
6
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