Setpoint processing, User Scale
The digital setpoint sent from the controller to the analog output channel must or can be changed in the device in order to
- reinterpret the measured value on the application side (e.g. convert the electrical 0...10 V signal of a pressure sensor into a pressure value)
- compensate for hardware dependency (keyword: calibration)
The output value/setpoint can be changed in 3 functional units, all three can be active at the same time:
- “User Scale”
- “User calibration”
- “Vendor calibration”
The “User Scale” functional unit is intended for reinterpretations/transformations of the setpoint, so “50 kg” in the controller can become “10 V” with Gain = 0.2. It is implemented as a linear transformation with gain/offset.
Parameters:
Index (hex) | Name | Data type | Meaning |
|---|---|---|---|
80n0:01 | Enable User Scale | BOOL | disabled by default, calculation only takes place if TRUE |
80n0:11 | User Scale Offset | SINT16 | is added directly in digits. |
80n0:12 | User Scale Gain | UINT16 | 1 bit corresponds to 2-16, so “1” corresponds to 0x7FFF/32767dec |
80nD:1D | User Scale Offset (REAL32) | REAL32 | – |
80nD:1E | User Scale Gain (REAL32) | REAL32 | – |
The intermediate value after this functional unit can be viewed in index 0x90n0:01.
Notice | ||
 | Changing the interface When the interface is changed, the gain and offset are reset to 1 and 0 respectively! | |