Siemens simovert masterdrives

Functions 09.2008
6SE7087-6QX70 (Version AK) Siemens AG
7-36 Compendium Motion Control SIMOVERT MASTERDRIVES
The backlash compensation is taken into account in the software limit
switches as follows:
If movement takes place over the software limit switch in the direction
of the backlash, the axis stops at the software limit switch plus
backlash.
This means that the unit itself is at the software limit switch but the
position setpoint is beyond it.
Example:
Negative position
(preferred position neg.)
Positive position
(preferred position plus)
Software limit switch plus: 100000 LU 100000 LU
Software limit switch minus: 50000 LU 50000 LU
Backlash: -100 LU 200 LU
Specified setpoint: 150000 LU 150000 LU
Output setpoint: 100100 LU 100000 LU
Actual-value: 100100 LU 100000 LU
Specified setpoint: 0 LU 0 LU
Output setpoint: 50000 LU 49800 LU
Actual-value: 50000 LU 49800 LU
Absolute positioning
In the case of absolute positioning, absolute equality is created
between the position setpoint and the actual position value.
Setpoint = actual value
The POS input enables the positioner and movement takes place to the
specified setpoint using the positioning movement. A new target
position can be set at any time by changing the position setpoint.
If the POS input is reset during absolute positioning, movement is
stopped immediately while maintaining the specified acceleration and
deceleration and the specified speed setpoint. If the POS input is set
again, the setpoint becomes valid again and the position setpoint is
approached again.
In the case of a linear axis, a position setpoint in the range -2
31
to
+2
31
-1 is possible, i.e. the range can be used to its full extent.
The software limit switches can be used with a linear axis.
In general, the use of a linear axis makes sense for limited movement
paths. Nevertheless, it must be ensured that the path representation fits
into the range.
Example:
A path is to have a resolution of 1/1000 mm = 1 µm:
4294.967297 could be represented with a 32 bit position setpoint of
-2
31
= -2147483648 [LU] to +2
31
-1 = 2147483647 [LU].
Because of the resolution in 2
n
steps and the mechanical coupling, a
actual-value weighting factor (AVWF) usually results that allows the
position setpoint to be converted to mechanical µm or [LU].
With linear axis