NORD Drivesystems BU0510 - Manual (Page 23)

3 Description of function
BU 0510 GB-3911 Subject to technical alterations 23
If the absolute encoder is not mounted on the motor shaft the gear ratio between the motor and the absolute
encoder must be parameterised. Rotations of the absolute encoder are converted to motor revolutions by the
inverter with the aid of parameter P607 "Speed Ratio" and P608 "Reduction Ratio".
n
M
: Motor rotations
n
M
= n
G
* Ü
b
/ U
n
n
G:
: Absolute encoder rotations
Ü
b
: Speed Ratio (P607[-02])
U
n
: Reduction Ratio (P608[-02])
Example: The absolute encoder is installed on the output side of the gear unit. The gear unit has a ratio of i = 26.3. The
following values are parameterised.
Speed ratio: 263; Reduction ratio: 10
The direction of rotation of the absolute encoder must comply with the direction of rotation of the motor. With a
positive output frequency (clockwise rotation) the actual position value must increase. If the direction of rotation
is not correct, this can be adjusted with a negative value in P607 "Speed Ratio".
The zero point of the axis can be adjusted with the aid of value which can be parameterised in parameter P609
[-02] "Offset Position". The offset is applied after the calculation. After changes to the Speed Ratio/Reduction
Ratio P607 [-02] and P608 [-02] the value in parameter P609 "Offset Position" must be entered again.
If the absolute encoder is not mounted on the motor shaft the gear ratio between the motor and the absolute
encoder must be parameterised. Rotations of the absolute encoder are converted to motor revolutions by the
inverter with the aid of parameter P607 "Speed Ratio" and P608 "Reduction Ratio".
n
M
: Motor rotations
n
M
= n
G
* Ü
b
/ U
n
n
G:
: Absolute encoder rotations
Ü
b
: Speed Ratio (P607[-02])
U
n
: Reduction Ratio (P608[-02])
Example: The absolute encoder is installed on the output side of the gear unit. The gear unit has a ratio of i = 26.3.
The following values are parameterised.
Speed ratio: 263; Reduction ratio: 10
The direction of rotation of the absolute encoder must comply with the direction of rotation of the motor. With a
positive output frequency (clockwise rotation) the actual position value must increase. If the direction of rotation
is not correct, this can be adjusted with a negative value in P607 "Speed Ratio".
The zero point of the axis can be adjusted with the aid of value which can be parameterised in parameter P609
[-02] "Offset Position". The offset is applied after the calculation. After changes to the Speed Ratio/Reduction
Ratio P607 [-02] and P608 [-02] the value in parameter P609 "Offset Position" must be entered again.
NOTE
The maximum possible position in parameter P615 "Maximum Position" results from the
resolution of the encoder and the Speed Ratio/Reduction Ratio (P607 and P608). Under no
circumstances can the maximum value exceed +/- 65535 (16Bit) rotations. Circulation is not
permissible. Endless items, which mainly run in a single direction must be realised with an
incremental encoder (See Section 3.2.1). Position setpoints should be internally limited to the
maximum possible value range.