> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wuji.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Maintenance

<Info>
  This page covers recovery from a lost connection, device reboot, what survives a reboot for parameters and calibration output, plus the user-serviceable boundary, daily checks, storage requirements, and firmware updates. To diagnose by symptom, see [Troubleshooting](/en/docs/wuji-glove/troubleshooting).
</Info>

## Connection Loss and Recovery

The glove has no joint motors, so recovery involves no stop behavior. Recovery escalates in three steps: free the client connection, reboot the device, then power-cycle it. The indicator light on the data acquisition board shows the current state.

### Connection States and the Indicator Light

The color and blink pattern of the indicator light map to the glove's current state, and a higher-priority state overrides the display of a lower-priority one:

| Indicator | Meaning | What to do |
| - | - | - |
| Cyan breathing | Standby, waiting for a host connection | The device is ready, so connect from the client |
| Cyan heartbeat | Running normally, streaming data | Nothing |
| Yellow very slow flash | Host connected but not pulling data | Confirm the client subscribed to the target stream |
| Red fast flash | Ethernet disconnected | Check the Ethernet cable and the adapter, see [Unable to connect to the glove](/en/docs/wuji-glove/troubleshooting#unable-to-connect-to-the-glove) |
| Red solid | Sensor hardware fault | Run `wuji doctor` to locate the faulty sensor, then contact support |

For all 11 states and their priorities, see [Product Introduction](/en/docs/wuji-glove/introduction#led-status-indicators).

### Free Up an Occupied Device Connection

Only one client holds the glove connection at a time. When `wuji viz` and an SDK script connect to the same glove one after another, the second one can't establish a connection. Exit the running client before switching, then connect again. For the full path when ping replies but the connection still fails, see [Software layer](/en/docs/wuji-glove/troubleshooting#software-layer).

### Reboot the Device

Reboot the glove from the SDK when a parameter needs a reboot to take effect, or when a stream stops updating for a long time:

```python theme={null}
glove.reboot()
```

After the reboot, the device returns to standby and accepts a new connection. If the SDK doesn't respond, power the device down and back up.

### What Survives a Reboot

A reboot or a power cycle leaves the following data intact:

| Data | Where it lives | How it takes effect |
| - | - | - |
| Device parameters (IP address, data port) | Device flash | The firmware writes them after `.set()` is called, with no extra save step |
| SDK-local parameters | `~/.wuji/sdk/params/` | Saved by `save_params()`, a separate mechanism from device flash persistence |
| Hand model | `left_hand.urdf` and `right_hand.urdf` under the current SDK user directory | Connected devices reload the model when the SDK user switches, with no reconnection |
| Tactile contact model | Stored per SDK user and glove serial number | Hot-reloaded after retraining or an SDK user switch |

Hand model writes go through an atomic replace, so a failed calibration keeps the last successful output and the run can be retried. For the storage rules, see [Where Calibration Is Stored](/en/docs/wuji-glove/sdk-data-reference/calibration#where-calibration-is-stored) in SDK Reference.

After an IP address change that leaves the host NIC and the glove on different subnets, the device drops off the scan list. Reconfigure the host NIC as described in [Unable to connect to the glove](/en/docs/wuji-glove/troubleshooting#unable-to-connect-to-the-glove) to bring it back.

### Checks After Recovery

```bash theme={null}
wuji devices
wuji doctor
wuji sub tactile --count 1
```

`wuji devices` lists the devices on the subnet, `wuji doctor` checks EMF disconnections and tactile dead points, rows, and columns, and `wuji sub tactile --count 1` exits once it receives one frame. All three passing means the link is back.

## Maintenance and Routine Checks

The glove body and cabling follow the wearing and routing requirements, daily checks cover appearance, cables, and the indicator light, and both firmware upgrades and log export run through the Wuji CLI.

### What You Can Service

| Part | What you can do | Notes |
| - | - | - |
| Fabric body and tactile areas | Put on and take off | Apply force at the palm when putting the glove on and on the fabric at the finger pads when taking it off. Avoid over-bending the sensor areas |
| Fingertip EMF receiver modules | Leave them in place | Keep force off the modules when taking the glove off, and don't pull on the modules or the back of the hand |
| Back-of-hand EMF transmitter module | Lift the surface pad to mount a tracker | The tracker mounting plate sits under the pad, each tracker model needs its own adapter, and the steps are in [Install the Tracker](/en/docs/wuji-glove/getting-started#step-tracker) |
| Data acquisition board and arm strap | Adjust the position along the strap | Keep the strap from being too tight, and leave slack in the routing when integrating into a fixed workstation or a robot arm |
| Cables and adapter | Plug, unplug, and route | Keep both ends of the USB-C to USB-C cable label side up, and use a USB-A to USB-C cable for power |

<Warning>
  The tactile array sits inside the palm-side fabric and the EMF receiver coils sit inside the fingertip housings, and neither comes apart on its own. Contact support if a sensor area shows physical damage.
</Warning>

### Daily Checks

Confirm before each use:

* The sensor areas lie flat, with no folds
* Fingers stay slightly bent and relaxed, without crossing the fingertip EMF modules or making a fist
* Both ends of the USB-C to USB-C cable face the same way, the Ethernet cable is seated, and the adapter indicator is lit
* The board indicator reaches cyan breathing, which means standby waiting for a host connection

Run `wuji doctor` regularly to check EMF disconnections and tactile dead points, rows, and columns. For usage, see [Wuji CLI health diagnostics](/en/docs/wuji-cli/doctor/).

<Warning>
  The tactile check needs the glove placed statically. Wearing or pressing it produces false positives.
</Warning>

### Storage and Environment

* **Storage**: keep the glove in a dry, cool place and avoid folding the sensor areas
* **Operating environment**: temperature -5 to 40 °C, humidity below 55% RH
* **Storage environment**: temperature -10 to 70 °C, humidity below 80% RH
* **EMF interference**: the sensing is sensitive to metal and ferromagnetic materials, so keep a clearance of 3 cm or more. Stay away from metal objects and electronics in use, and keep the hand within 30 cm of the transmitter coil

### Firmware and Software Updates

The Wuji CLI pulls the matching firmware version from the official firmware source, verifies it, flashes it, and prints a per-device report:

```bash theme={null}
wuji upgrade --check
wuji upgrade --type wuji_glove
```

`--check` is read-only and lists which devices have a firmware update. `--type wuji_glove` upgrades every glove in scope to its own latest version, and each device reboots into the new firmware once flashing finishes. For the full scope and action options, see [Wuji CLI firmware upgrade](/en/docs/wuji-cli/firmware-upgrade/).

The calibration interfaces have minimum firmware and SDK versions. For the pairing, see the component version table in [Release Notes](/en/release-notes).

### Support

Export a log support bundle before contacting support:

```bash theme={null}
wuji logs export --days 7
```

The command writes a timestamped ZIP bundle to the current directory, containing text logs, host and device diagnostics, hand model calibration recordings, and a file manifest. Send the bundle to [support@wuji.tech](mailto:support@wuji.tech) together with the glove serial number, firmware version, SDK and CLI versions, operating system version, and reproduction steps. For the options, see [Wuji CLI log export](/en/docs/wuji-cli/logs/).


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