PRIME MOTIONE-STOP, feed hold and reset
There are three ways to stop the machine from Prime Motion. They are not interchangeable.
| Control | Where | What it does | Can you carry on? |
|---|---|---|---|
| Hold | Command rail on Control | A controlled stop; the job keeps its place | Yes, with Resume |
| Stop | Command rail, first slot, during a job | Ends the job | No |
| E-STOP | Right end of the navigation bar, every screen | Cancels the job, or resets the controller | No |
Hold — pause and look
Hold decelerates the machine to a controlled stop. The job keeps its place, so Resume continues from exactly where it stopped. If the program had the spindle running, it is restarted and given its spin-up time before cutting continues.
Use Hold to check a cut, clear chips, or listen to a noise you do not like. It costs nothing.
While held, the rail shows Resume. The Hold button reads Hold ▪ S Off when the spindle has also stopped. During the spin-up after Resume it reads S and the speed with three dots.
A parked controller can report Door while the job is held: Hold first pauses the job, then the controller parks it with the spindle stopped and tool clear. The state tag shows that reported state. Resume releases the parked job.
If the machine is no longer where the job paused when you tap Resume, Prime Motion refuses to carry on from the wrong place and offers Return (go back to the pause point, then resume) or Resume anyway; see Single-block running and resuming after a move.
Stop — end the job
Stop replaces Run in the first rail slot while a job is active. One tap ends the job: the controller is reset and the job is recorded in History as Cancelled. It does not ask first, and it cannot be resumed. To start again, use Start; to pick up part-way through, see Recovering an interrupted job.
E-STOP — stop everything
Three taps, each within one second of the last. The panel brightens with each tap and dots along its bottom show the count. Pause for more than a second and the count starts again. Three taps rather than one is deliberate: an on-screen button that fired on a single accidental brush would go off constantly in a workshop.
| When | What E-STOP does |
|---|---|
| A job is running, held, spinning up, changing tools or measuring a tool | Cancels the job and resets the controller; History records Cancelled |
| Anything else | Resets the controller |
E-STOP sits outside every drawer and shaded panel, so it is always reachable. A paired remote browser can use it too, with the same three taps; see Remote access.
After an E-STOP or a Stop
A reset clears the controller's tool-length offset. If you had measured the tool, the next Start may be refused with Work Zero Is No Longer Valid: re-set Z, or measure the tool again, before continuing. A reset during motion may also leave the controller in alarm, depending on the firmware; see below.
After an alarm
An alarm is the controller stopping itself: a limit switch was hit, a probe failed, the machine was reset while moving. While in alarm the controller refuses motion. Clearing it lets the machine accept commands again; it does not fix what caused it.
When the controller reports an alarm, a machine condition drawer appears at the top of Control, above any other drawer. Its title names the code, such as ALARM:1, and its text explains it. Its one button is the remedy that fits that alarm:
| Button | What it does | Offered for, for example |
|---|---|---|
| Unlock | Resets the controller, then unlocks it ($X) | A soft limit (ALARM:2) |
| Re-home | Unlocks, then runs a homing cycle | A hard limit (ALARM:1), reset while moving (ALARM:3), homing failures, homing required (ALARM:11) |
| Soft reset | Resets the controller | Conditions a reset clears |
| Probing | Opens the Probe drawer | A failed probe (ALARM:4, ALARM:5) |
| Firmware | Opens Settings → Firmware | A setting problem (ALARM:9, ALARM:14) |
On a machine with homing disabled ($22=0), Unlock replaces Re-home and Unlock & home. It sends $X without a homing command. Unlocking does not recover a lost position: check the work zero before starting again.
Some alarms have no on-screen remedy because the fix is physical: release the machine's emergency stop (grblHAL ALARM:10), check a motor driver (ALARM:17), or jog off a limit switch (ALARM:12). The drawer then explains without a button.
The command rail can also offer the remedy in its first slot, labelled Unlock, Unlock & home or Soft reset. It opens a Reset Alarm drawer: This will clear the alarm state and unlock the machine. Ensure it is safe to proceed. with Cancel and Unlock. Unlock there runs the remedy named on the rail, so for Unlock & home it also homes.
Once the controller accepts the remedy and returns to Idle, Start becomes available for the loaded file. The failed attempt remains in History. You do not need another reset just to clear the ended job. Starting again runs the file from its beginning, so first correct the cause, check the work zero and make sure repeating the cut is appropriate.
In this soft-limit example, unlocking has not corrected the misplaced work zero: Safety is still red. Restore a valid stock-corner zero within machine travel before starting again.
A successful rerun creates its own Completed entry; it does not replace the earlier Failed entry. In the example below, both attempts used the same posted roughing file. The successful attempt completed all 3,115 lines.
