Glossary · Automation fundamentals, platforms and components
Zero point
Also known as: Zero, Reference point, Home position
German: Nullpunkt
In automation and measurement, the zero point is the reference from which values are measured: the output of a sensor at zero measured quantity (zero offset), or, in motion control and CNC, the reference position of an axis or coordinate system, established by referencing (homing) or set as a workpiece zero.
- Automation components
In one sentence
The zero point is the reference for measured values: a sensor's zero offset, or an axis or workpiece reference position in motion control and CNC.
Example
After replacing the encoder, the service technician runs the homing routine to re-establish the axis zero point before production resumes.
How it applies
- Measurement: Zero offsets drift over time and with temperature. Zero adjustment, taring in Weighing technology and Calibration keep measurements correct; Sensor drift shows up first at the zero point.
- Motion control: Axes with incremental encoders must be referenced after power-up; absolute encoders keep their position. A wrong zero point can cause collisions or out-of-tolerance parts.
- Documentation: Service manuals describe when and how zero points are re-established, for example after replacing a motor, encoder or sensor, and how the result is verified. Parameter lists should mark zero offset values that must not be changed casually.
Machine zero vs. workpiece zero
In CNC, the machine zero is fixed by the manufacturer. The workpiece zero is set by the operator for each job. Mixing them up is a classic cause of crashes.