Technical data

Technology objects
CPU 317T: Technology Functions
3-10 A5E00251798-03
3.1.7 Absolute encoder adjustment
The technology functions MC_Home (Mode = 5) and MC_ExternalEncoder
(Mode = 6) are used to add the absolute value encoder offset for axis operation
and external encoders.
The current position of an axis with absolute value encoder is set to a required
value. This shifts (offsets) the absolute position of the absolute value encoder. This
offset is stored permanently and remains in effect for use in the next adjustment of
the absolute value encoder. Execute this function once when you commission the
PLC.
The offset is cleared if the Technology CPU changes from STOP to RUN and the
TO is invalid (for example, if the Technology CPU is started up without MMC.)
To adjust the absolute value encoder:
1. Disable the software limit switches, because otherwise you can not adjust the
absolute value encoders.
2. Move the axis to the relevant reference position, then adjust the absolute value
encoder (MC_Home or MC_ExternalEncoder technology function)
3. Enable the software limit switches as required.
Note that the adjustment of the absolute value encoder only offsets the encoder
value. The offset of the absolute value encoder adjustment and the value of the
absolute value encoder are decisive for determining the position after POWER
OFF or restart (MC_Reset, Restart = TRUE.) During operation, the current actual
position is also affected by the modulo settings of the axis, and by positioning or
position adjustment control commands.
Absolute
value
encoder
Encoder position
Offset by absolute
value encoder
adjustment
(permanent)
Correction in runtime
(MC_Home: Mode 3, 4)
Actual position value
of the axis
Effective on
POWER ON