Troubleshooting¶

By symptom. The error flags and what clears them are in Errors and recovery. The faults in the firmware and the software that are known and not yet fixed, and what to do until they are, are on Known issues.

The gripper does not answer¶

Symptom	Check
nothing at all	the 24 V on the cable; the cable's pinout (a wrong one has destroyed the driver already); the node ID the host uses; 1 Mbit/s on the adapter; the termination (about 60 Ω across CANH and CANL, unpowered)
answers, then stops answering	the watchdog ran out and the host did not notice; a loose M8 connector; a second device with the same node ID
the GUI shows No connection	the COM port of the CANvas adapter; another program holding the port; the CAN ID in the GUI

It does not move¶

flowchart TD
    A([The gripper does not move]) --> B{Does it answer on CAN?}
    B -- no --> C[24 V on the cable, the pinout, the node ID,<br>1 Mbit/s, the termination]
    B -- yes --> D{Calibrated?}
    D -- no --> E[Run the gripper calibration;<br>a self-built gripper: the motor calibration first]
    D -- yes --> F{An error flag set?}
    F -- yes --> G[Clear it; if it comes back,<br>Errors and recovery names the cause]
    F -- no --> H{Activate and action bits at 1?}
    H -- no --> I[Send the command with activate = 1 and action = 1]
    H -- yes --> J[The command equals the previous one:<br>change the speed or the current by one]

Symptom	Check
calibrated, activated, no error, no motion	the action bit of the command is 0; the command is identical to the previous one (change the speed or the current by one to repeat a move)
Not calibrated after power-up	normal: run the gripper calibration
an error is shown	Errors and recovery: clear it, then look at the cause if it comes back
the driver reports Not calibrated in State_of_Errors and `#Error`	the motor itself is not calibrated (a self-built gripper): Driver configuration

Calibration¶

Symptom	Cause
the jaws move to one end and stop; after 30 s the gripper is still not calibrated	the other end is blocked, or the mechanism is too stiff for the calibration's 500 mA: a tight rail, a pinion pressed too hard into the racks, debris in the racks
the jaws jitter and do not travel	a phase of the motor not connected (self-built), or the motor not calibrated
255 is not fully closed, or 0 not fully open	something stopped the jaws short of the end during calibration; calibrate again with the stroke free

The grip¶

Symptom	Cause
the object slips	the current too low for the object; the finger faces: foam on the pinch jaws, or the fin-ray fingers
the object is crushed	the current too high; a hard object takes the full force at once
object detected while nothing is there	the current limit too low for the mechanism's friction at that speed; raise the current a little or lower the speed
the gripper stops with a temperature error after a while	a long hold at a high current; hold with the lowest current that keeps the object
the jaws creep or hum when holding	the position loop against a hard object; lower the current, or hold a soft object with a position slightly beyond the contact

Noise and heat¶

A gimbal motor under field-oriented control is quiet; a grinding noise is the rack and pinion without grease, or debris. The motor gets warm in use and hot under a long grip; the thermistor stops it at 75 °C. A self-built gripper without a thermistor in the windings has no such protection.

After a firmware update¶

If the gripper does not calibrate or behaves oddly after an update, check the driver's configuration over UART: #Gripper (gripper mode, 1), #Term (the thermistor, 1) and #Info (the motor calibration and parameters). A release note says when an update clears the configuration; Driver configuration restores it.

Getting help¶

Support says where to ask and what to include; the gripper's status and #Info's output are the first things.

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