HEIDENHAIN PROFIBUS-DP (DPV0) - Manual (Page 35)

Encoder and Gateway functionality, DPV0
35
5.4.4 Scaling function control
The scaling function converts the encoder’s physical absolute
position value by means of software in order to change the
resolution of the encoder. Class 2 functionality must be enabled in
order to use the scaling function. The parameters “Measuring
units per revolution” and “Total measuring range in measuring
steps” are the scaling parameters set by the parameter function
in octet 10 to 17. Scaling is active only if the control bit for the
scaling function is set. When the scaling function control bit is set
to 0, the scaling function is disabled.
Singleturn encoders up to 31 bit and multiturn encoders up to
37 bits resolution are supported by the PROFIBUS gateway.
When using encoders with higher resolution than 31 bits, the
singleturn resolution of the encoder will automatically be reduced
as much as needed to fit into the 32 bit structure.
For example, if a 37 bit encoder with a 25 bit singleturn and 12 bit
multiturn resolution is used, the singleturn resolution will be
reduced from 25 to 19 bit, and the multiturn resolution will still be
12 bit. (19 bit singleturn+12 bit multiturn = 31 bit total resolution).
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.
5.4.5 Measuring units per revolution
The total measuring range is calculated by multiplying the
singleturn resolution with the number of distinguishable
revolutions.
The default settings for singleturn encoders are:
Measuring units per revolution= 8192 (2 13 )
Total measuring range in measuring units= 8192 (2 13 x 2 0 )
The default settings for 25 bit multiturn encoders are:
Measuring units per revolution= 8192 (2 13 )
Total measuring range in measuring units= 33554432 (2 13 x 2 12 )