2 scaling formulas, 6 preset value, 1 overview – ifm electronic RN7003 User Manual
Page 16
CANopen encoder
16
Format of the singleturn scaling parameters
Byte
3
2
1
0
Bit
31 - 24
23 - 16
15 - 8
7 - 0
Data
2
31
- 2
24
2
23
- 2
16
2
15
- 2
8
2
7
- 2
0
object 6001h - steps per revolution
Format of the multiturn scaling parameters
Byte
3
2
1
0
Bit
31 - 24
23 - 16
15 - 8
7 - 0
Data
2
31
- 2
24
2
23
- 2
16
2
15
- 2
8
2
7
- 2
0
object 6002h - total measuring range in steps
Scaling formulas
6.5.2
The scaling function used in the CANopen encoder is limited to a singleturn
resolution within a step� After the download of new scaling parameters the preset
function should be used to set the start point of the encoder�
Only change the scaling function parameters if the shaft is stationary�
In the following formula a 25-bit multiturn encoder with a singleturn resolution of 13
bits is used as an example�
Formula for the multiturn scaling function:
A = (singleturn_position x steps_per_revolution) / 8192
output_position = (revolution_number x steps_per_revolution) + A
Where: singleturn_position = absolute singleturn position value
revolution_number = absolute multiturn number
Preset value
6.6
Overview
6.6.1
The preset function (object 0x6003h) supports the adaptation of the encoder to the
mechanical zero point or to a preset value� The preset function is used after the
scaling function� The preset value is then provided as a measured value�
A preset value is determined by the encoder as follows: