Wuhan Huazhong Numerical Control HNC-18M, Operator'S Manual, Page: 34 / 119

2 Set up
20
Homing (Reference–point Approach)
In homing (sometimes called reference point approach), there is a
reference point for each axis. These reference points are used to set
up the machine’s coordinate system. Homing should always be
performed each time the machine is powered on. By homing each
time the machine is powered on, the axis’ original positions are the
same as the previous time.
Shown below is a diagram of a typical axis homing. The present
location in red is a distance from the Origin. When the axis homes,
the axis motion moves the present location toward the origin until it
touches the Reference Switch (RSW).
Now it is roughly located near the origin. Next, machine control
moves the tool very slowly until the “home signal” encoder signal is
triggered. This is the exact location of the origin, accurate to the
resolution of the encoder.
Origin
Reference
Switch (RSW)
Motion Axis
Tool location
Origin
Reference
Switch (RSW)
Motion Axis
Present location