Siemens SIMATIC FM 452 Manual page 80

Machine Data and Cam Data
8.4 Absolute Encoder Adjustment
Definition
With absolute encoder adjustment and the reference point coordinate, there is a
defined correlation between the range of values of the encoder and the coordinate
system of the axis.
Address Name
48.0 ENC_ADJ
Establishing the Correct Absolute Encoder Adjustment
After the initial parameter assignment, further steps are necessary to establish the
correct relationship between the encoder and the coordinate system. The
sequence shown below is the sequence when using the parameter assignment
user interface.
1. Move the axis to a defined reproducible point that you know and that is
physically unique.
This could be, for example, the "end software limit switch".
2. Start the "set reference point" setting with the coordinate of the point defined in
step 1.
The FM 452 now determines an encoder value, the absolute encoder
adjustment, for the reference-point coordinate entered in the machine data. You
can read out this value with the user interface in the service dialog.
3. Enter the read-out value in the machine data "absolute encoder adjustment".
4. Save the machine data.
5. Download the data in HW Config to the CPU.
6. To activate the data, run a warm restart on the CPU.
Note
You make this adjustment once during installation and startup. The FM 452 is
synchronized following parameter assignment during startup as soon as a
complete, error-free frame is received from the encoder following startup.
Data in the Parameter DB
Address Name
44.0 REFPT
8-12
Type Initial Value
DINT L#0 Absolute encoder adjustment
Range:
Type Initial Value
DINT L#0 Reference point coordinate:
Range:
Comment
25
0 to (2 –1)
Comment
– 1 000 000 000 m to
+ 1 000 000 000 m
FM 452 Electronic Cam Controller
C79000-G7076-C452-04