HEIDENHAIN PROFINET - Manual (Page 74)

Functional description of the encoder
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Note: If scaling is used the preset function shall be used after
the scaling function to ensure that the preset value is
entered in the current measuring unit.
Note: There is no preset activated when the preset value is
written to the encoder. The preset function is controlled
by bits in the control and status words (G1_STW and
G1_ZSW) and bit in the operating parameters. The pre-
set value is used when a preset is requested by bit 12
in the control word (G1_STW).
7.8 Scaling function parameters
The scaling function converts the encoder’s physical absolute po-
sition value by means of software in order to change the resolu-
tion of the encoder. The scaling parameters will only be activated
if the parameter Class 4 functionality and Scaling function control
are enabled. The permissible value range for the scaling is limited
by the resolution of the encoder. The scaling parameters are se-
curely stored in the IO controller and are reloaded into the encod-
er at each power-up.
7.8.1 Measuring units per revolution
This parameter sets the single turn resolution of the encoder. In
other words it is the number of different measuring steps during
one revolution of the encoder.
Example:
For a 13-bit encoder with a single turn resolution of 13 bits the
permissible value range for "Measuring units per revolution" is be-
tween 2 0 and 2 13 (8192).
Parameter Meaning Data type
Measuring units
per revolution
The single turn resolution
in measuring steps
Unsigned 32
Measuring units
per revolution
64 bit
The single turn resolution
in measuring steps for en-
coders with a resolution
exceeding 32 bits.
Unsigned 64
Table 40 Measuring units per revolution
Note: After downloading new scaling parameters, the preset
function must be used to set the encoder starting
point to absolute position 0 or to any required starting
position within the scaled operating range.