Siemens SIMATIC S5 Manual page 141

Function block for assigning parameters to the IP 267
DW 8 - AL - This value describes the required plant sections (stepper
7-18
motor, gears, leadscrew pitch). The user determines this
value by dividing the number of pulses per revolution of
the motor by the path (or angle) per revolution of the
motor. The ratio of any gearing used must be taken into
account.
e.g. linear axis :
Motor data
Axis data
Resolution (Res.)
In this case, the length is measured in mm. The minimum
traversing path of a positioning job is therefore 1 mm.
The maximum traversing path is the maximum number of
pulses divided by the resolution (up to 32767 length units
or angular units).
Max. numb. of pulses : 1,048,575 pulses (20 bits)
Resolution
Max. path
Many applications demand a higher positioning accuracy,
which can be achieved by multiplying the parameter Res.
several times by the factor 0.1. In the example above, the
user may also enter 20 or 2, instead of 200, for the
parameter Res.
The positioning accuracy thus changes from 1 mm to
100 µm or 10 µm; consequently, the maximum traversing
path is reduced from 5242 mm to 3276.7 mm or
327.67 mm. Additionally, the length unit [mm] assigned
to the path in DW 13 changes to 100 µm or 10 µm.
If the resolution value is no integer value, a gearing with a
suitable ratio should be selected to ensure that the ma-
ximum traversing path (angle of rotation) will not exceed
the permissible limits.
IP 267
: 200 pulses/rev.
: 1.0 mm/rev.
: 200 pulses/mm
: 200 pulses/mm
: 5242 mm
EWA 4NEB 812 6061-02a