Various operating modes/scaling are available for MOVI‑C® decentralized drive electonics in the DBC communication variant. For a description of the functions, refer to the operating instructions of the respective device. You can download the documentation from the SEW-EURODRIVE website (www.sew-eurodrive.com) in various languages.
Scaling of a setpoint via analog input
At the analog input, the measured physical value of the analog input is converted into a scaled value without unit for the voltage input/current input according to the following formula:
Actual value
Parameter Input voltage or Input current
Offset
Parameter Voltage offset scaling or Current offset scaling
Conversion factor
Fixed value:
for voltage: 1000/1 V
for current: 500/1 mA
Numerator scaling
Parameter Numerator scaling
Denominator scaling
Parameter Denominator scaling
The scaled value without unit is converted into a setpoint according to the following formula:
[Setpoint]
The unit depends on the position at which the analog setpoint is to be used.
Scaled value
Parameter Scaled value
Number of decimal places
The number of decimal places depends on the position at which the analog setpoint is to be used:
For use with user unit (e.g. speed setpoint), it is defined by the user in the parameter Number of decimal places (parameter group Drive trains > Drive train DT > User unit).
For use with system units (e.g. torque setpoint), it is defined by the inverter and can be determined via the tool tip of the parameter.
The calculated setpoint is used like a process output data word. It can be selected as source of the setpoint in the parameter group Setpoints > Setpoint value connection.
Example: Calculation of a speed setpoint
The following quantities are given in the example:
Quantity
Value
Function of the analog input
0 – 10 V input
Actual value (parameter Input voltage)
7.5 V
Offset (parameter Voltage offset scaling)
2.5 V
Conversion factor
1000/1 V
Numerator scaling
1
Denominator scaling
5
User unit
Rev. min-1
Number of decimal places
2
The scaled value is calculated as follows:
The scaled value is used as speed setpoint in the setpoint connection after the following conversion: