Siemens SINUMERIK 840D sl Function Manual page 437

2.3.6 Actual-value processing
Actual-value resolution
In order to be able to create a correctly closed position control loop, the control system must
be informed of the valid actual-value resolution. The axis-specific machine data below are
used for this.
The control calculates the actual-value resolution from the settings made in the MD. The
control parameter sets of the position control are identified as servo parameter sets.
The machining process of the machine forms the basis of the position actual-value
acquisition.
Direct measuring system (DM) is on machine directly:
Indirect measuring system (IM) is on motor indirectly:
Depending on the type of axis (linear axis, rotary axis) and the type of actual-value
acquisition (directly at the machine, indirectly at the motor), the following machine data must
be parameterized to calculate the actual-value resolution:
Machine data
MD30300 $MA_IS_ROT_AX
MD31000 $MA_ENC_IS_LINEAR[n]
MD31010 $MA_ENC_GRID_POINT_DIST[n]
MD34320 $MA_ENC_INVERS[n]
MD31040 $MA_ENC_IS_DIRECT[n]
MD31044 $MA_ENC_IS_DIRECT2[n]
MD31020 $MA_ENC_RESOL[n]
MD31030 $MA_LEADSCREW_PITCH
MD31050 $MA_DRIVE_AX_RATIO_DENOM[n]
MD31060 $MA_DRIVE_AX_RATIO_NUMERA[n]
MD31070 $MA_DRIVE_ENC_RATIO_DENOM[n]
MD31080 $MA_DRIVE_ENC_RATIO_NUMERA[n]
- = Does not apply to this combination
* The encoder on the motor side is a built-in encoder and, therefore, does not have a measuring gear unit.
The transmission ratio is always 1:1.
Basic logic functions: Velocities, Setpoint/Actual Value Systems, Closed-Loop Control (G2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Linear axis Linear axis
Linear scale/ Encoder
or as direct on
measuring motor
system
0 0
1 0
Spacing -
Opposite -
direction
- / (1) 0
- / (1) 0
- Pulses/
rev
- mm/rev.
- Load rev.
- Motor
rev. if infeed
gear
available
- Encoder rev.
- Motor-
side encoder*
Detailed description
2.3 Setpoint /actual-value system
Load-side encoder
Motor-side encoder
Rotary axis
Encoder Encoder
on on
machine motor
and/or tool
0 1
0 0
- -
- -
1 0
1 0
Pulses/ Pulses/r
rev ev
mm/rev. -
- Load
rev.
- Motor
rev.
Encoder Encoder
rev. rev.
Motor Motor
rev. rev.
Encoder
on
machine
and/or tool
1
0
-
-
1
1
Pulses/
rev
-
See
note
See
note
Encoder
rev.
Load
rev.
49