Faults

A fault switches motion off. The Fault badge on the Control screen turns red, the status banner turns red with the fault's remedy, the machine refuses to enable motion, and a running test is ended.

The machine re-checks every fault condition continuously:

• Most faults clear by themselves when their cause goes away (releasing the emergency stop, for example).
• SERVO_STALL is the exception: it stays until you acknowledge it.
• A stopped core (COG, WATCHDOG, SERVO_COMMUNICATION) doesn't come back by itself: power-cycle the machine.

Click Disable motion while a fault is showing

The machine remembers that you asked for motion. If the fault clears by itself, motion comes back on without another click. Clicking Disable motion while faulted withdraws the request, so the machine stays off until you enable it again. This is why the button offers a disable whenever a fault is showing.

Only one fault is shown at a time: the first in the order below. Fix it and the next one, if any, appears.

Reconnecting the app never clears a fault and never restarts the machine.

COG

A processor core in the controller stopped running.

The controller runs each job (motion, force reading, communication, logging) on its own core. One of them is no longer running.

What to do: Power-cycle the machine. If it comes back, note what the machine was doing and report it.

WATCHDOG

A task in the controller stopped checking in.

Each core has to report in regularly. One missed its deadline, so the machine no longer trusts it.

What to do: Power-cycle the machine. If it repeats, report it with the session log.

ESD_POWER

The emergency stop circuit has no power.

The DC supply for the emergency stop chain is off: the ON button hasn't been pressed, or the supply has dropped.

What to do: Press ON (power-up sequence). If it stays, check the supply and wiring of the emergency stop chain.

ESD_SWITCH

The emergency stop is pressed.

The emergency stop switch is open, which also removes power from the drive.

What to do: Make sure the machine is safe, then release the emergency stop.

ESD_UPPER

The upper emergency-stop limit tripped.

The upper limit input of the emergency stop chain is active: the carriage ran past the top of its travel. This is the hard limit, separate from the upper end stop that raises a restriction.

What to do: Motion stays off while this is tripped, so the carriage can't be jogged off it: move it back by hand. Then find out why it over-travelled: Position Max, homing and the end stop are the usual suspects.

ESD_LOWER

The lower emergency-stop limit tripped.

As ESD_UPPER, at the bottom of travel.

What to do: As ESD_UPPER.

SERVO_COMMUNICATION

The motor control loop is not running.

Despite the name, this is not a cable to the drive: it means the core that generates step pulses and closes the position loop has stopped ticking.

What to do: Power-cycle the machine. If it repeats, report it.

FORCE_GAUGE_COMMUNICATION

The load cell amplifier stopped answering.

The controller reads the load cell through an ADC on the force gauge board. It retried and got no reply.

What to do: Check the cable between the controller and the force gauge board and that the board has power. The fault clears by itself when readings resume. If it doesn't, power-cycle.

SERVO_STALL

The carriage stopped following the drive.

The machine compares where it is driving the carriage with where the encoder says it is. It declares a stall when any of these happens:

• the position error passes 2 mm;
• the position error stays above 1 mm;
• about 1 mm of step pulses go out and the encoder covers too little of it.

Typical causes: the carriage hit something or reached the end of its travel, the sample is stiffer than the motor can pull, Acceleration Max or Velocity Max is more than the motor can deliver, the drive is off, or the encoder isn't counting.

What to do:

1. Clear whatever is blocking the carriage.
2. Click Clear stall (disable motion). The Fault badge returns to NONE.
3. Click Enable motion.

A stall latches on purpose. Disabling motion is what makes the stall condition go away, so a stall that cleared itself would re-enable and drive into the same obstruction again.

If it stalls with nothing in the way, run the motor calibration: the drive and encoder check finds wiring and steps/mm problems, and the motion calibration tells you whether Acceleration Max is too high.