HEIDENHAIN PROFINET - Manual (Page 80)

Functional description of the encoder
80
7.10 Velocity measuring units
This parameter defines the coding of the velocity measuring units
used to configure the signals NIST_A and NIST_B. Standard tele-
gram 81 has no velocity information included and the encoder
does not use the velocity unit information in this case. Telegram
82,83,84 and 59001 includes velocity output and needs a declara-
tion of the velocity measuring unit.
Parameter Meaning Value
Velocity measuring
units
Definition of the units for
the encoder velocity output
value
See below
Velocity measuring units Value
Steps/s 0
Steps/100ms 1
Steps/10ms 2
RPM 3
Table 42 Velocity measuring units
The velocity calculations are made with a maximum of 19 bits
resolution. If the resolution is higher than 2 19 , the value used for
velocity calculations is automatically reduced to 2 19 .
Example:
For a 37 bit multi turn encoder with a 2
25 single turn resolution
and a 2 12 multi turn resolution, the maximum single turn value for
velocity calculations will be 2 19 . For a single turn encoder the max-
imum resolution can be up to 31 bit, but the value used for veloci-
ty calculations will in this case also be 2 19 .
Note: In case of the steps/s unit, an average is made over
200 ms and the value is multiplied by 5.
Note: If scaling has been set on the device the velocity calcu-
lation is based on the scaled position value. Conse-
quently the accuracy of the velocity value is dependent
of the scaling set to the device.