PRIME MOTIONSoft limits and travel
Travel is how far each axis can physically move. Several separate protections keep a program or a jog inside it, and it pays to know which one you are looking at.
Where the travel figures come from
Your machine profile carries travel for the model and variant you chose. Once connected, Prime Motion reads the controller's own travel settings ($130, $131, $132) and uses those instead: the controller is the thing that moves. Settings → Connection → Travel Limits shows the figures in use and where they came from.
Why limits need homing
Every limit is written in machine coordinates, and machine coordinates mean something only after homing. Before homing, the controller counts from wherever the gantry was at power-on, so a limit at "X 810" refers to nothing in particular. This is the reason for the homing gate.
The four protections
| Protection | Who enforces it | When | What happens |
|---|---|---|---|
Hard limits ($21) | The controller | A limit switch is hit | The machine stops at once in ALARM:1 and must be re-homed |
Soft limits ($20) | The controller | A move would leave travel | The move is refused and the controller enters ALARM:2 |
| Work Envelope Exceeded | Prime Motion | When you tap Start | The start is refused, with the overrun per axis |
| Stop Jog at Limits | Prime Motion | While jogging | A jog is shortened to the edge of travel, or blocked at it |
The first two live in your controller and are set in Settings → Firmware. The last two are Prime Motion's, switched in Settings → Safety.
Work Envelope Exceeded
With Soft Limit Warning on (the default), Start compares the whole program, placed at your current work zero, with the machine's travel. If it does not fit, the Work Envelope Exceeded drawer lists each axis that overruns, for example X: job needs 10.0 to 850.0 mm, limit is 0.0 to 800.0 mm (50.0 mm over), and nothing is sent. There is no run-anyway button: move work zero, or the stock, so the job fits.
Stop Jog at Limits
With Stop Jog at Limits on (the default), a jog that would pass the edge of travel is shortened to the edge, and a jog toward an edge you are already at is blocked. The Notes card says so, for example Jog shortened to X limit or At X+ machine limit — jog blocked.
The safety colours on a loaded program
When a program loads, Prime Motion checks every move against the active machine and colours the Safety toggle on the Control screen's view, with the offending moves highlighted in the toolpath:
| Finding | Colour |
|---|---|
| A move leaves the machine's travel | Red — critical |
| A move goes deeper than the machine's Z travel allows below work zero | Red — critical (checked once Z zero is set) |
| A move comes within 5 mm of the edge of travel | Amber — warning |
| A rapid move ends below the top of the work (Z0) | Amber — warning |
The colours are information to act on before you start. A red Safety toggle does not by itself block Start; the envelope check above does that.