Scaling of process data
The process data are always transmitted as fixed-point values to make for simple calculation in the ongoing system process. Parameters with identical units of measurement receive the same scaling so that the higher-level automation device can directly compare the set and actual values in the application program. There are three process data types:
- Speed in rpm
- Current in % IN (nominal current)
- Ramp in ms
The different versions of the control or status word are coded as bit field and will be described in a separate chapter.
Process data | Type | Resolution | Reference | Range |
|---|---|---|---|---|
Speed setpoint / Actual speed value / Speed limit slip compensation | Integer 16 | 1 digit = 0.2 rpm |
| -6553.6 – 0 – +6553.4 rpm 8000hex – 0 – 7FFFhex |
Relative speed setpoint [%] / Relative actual speed value [%] | Integer 16 | 1 digit = 0.0061% (4000hex = 100 %) | Maximum speed of the inverter | - 200 % – 0 – + 200% - 0.0061 % 8000hex – 0 – 7FFFhex |
Apparent current actual value / Actual active current value / Current setpoint Current limitation | Integer 16 | 1 digit = 0.1% IN | Nominal current of the frequency inverter | -3276.8 % – 0 – +3276.7 % 8000hex .– 0 – 7FFFhex |
Process ramp up / process ramp down | Unsigned 16 | 1 digit = 1 ms | delta-f = 100 Hz | 0 ms – 65535 ms 0000hex – FFFFhex |
Positive speed values correspond to a CW rotation with proper connection of the motor.
