Scaling refers to converting the transducer feedback into meaningful units. The RMC uses the Scale and Offset parameters to convert the transducer Counts or Raw Counts into measurement units (position, velocity, pressure, force). For example, the Voltage returned by an analog position transducer must be converted to positions in order to be useful for control. In order to correctly convert the transducer feedback to useful units, you must calculate the Scale and Offset parameters.
The RMC uses the default terms Position Units (pu), Pressure Units (Pr), and Force Units (Fr) for the scaled feedback. You can change these to feedback units of your preference by choosing from a list or entering a custom unit. See Display Units for details.
Calculating the Scale and Offset
RMCTools provides Scale/Offset wizards to help you calculate the Scale and Offset parameters. You can also calculate the parameters manually.
Scale/Offset Wizards
To access the Scale/Offset wizard, in Axis Tools, in the Axis Parameters pane, click the Setup tab. Expand the Tools and Wizards section. Click Launch to open the Scale/Offset Wizard.
Note:
Before using the Scale/Offset Wizard, you must define
the axes and set the transducer type parameters.
Manual Calculation
The methods of calculating the scale and offset parameters depends on the axis type. See the scaling topic for your axis type:
Scale and Offset Parameters
The following parameters converting the transducer feedback Counts into meaningful units. Each axis, whether a control axis or reference axis, has these parameters:
Scale
On a linear axis, the Position, Pressure, Force, or Velocity Scale defines the number of Actual units (position, velocity, pressure or force) per count or volt returned from the transducer.
Offset
On a linear axis, the Position, Pressure, Force, or Velocity Offset moves the zero point of the Actual units to where the user wants it.
On a rotary axis, the Position Offset defines the lower range of the position range.
Count Offset
This parameter is used for Absolute Rotary axes to determine where the zero point of the counts should be.
Position Unwind
On a rotary axis, the Position Unwind defines the span of the position range.
Count Unwind
On a rotary axis, the Count Unwind defines the range of counts over which the Position Unwind spans.
Provides an offset value that is applied before the Scale and Offset parameters.
Provides an offset value that is applied before the Scale and Offset parameters.
This parameter is used for bidirectional load cells, which typically have a slight gain difference between the positive and negative side.
See Also
Copyright © 2024 Delta Computer Systems, Inc. dba Delta Motion