Troubleshooting

This section focuses on the most common operational issues and how to resolve or diagnose them using the screen and web interface.

No GPS Lock / Sync Searching

Symptoms:

  • Satellite count is low or zero.

  • Sync indicator shows searching.

Actions:

  • Verify the GPS antenna is connected to the BNC port.

  • Move to an open area with clear sky view.

  • Wait a few minutes for initial acquisition.

Transmit Button Disabled

Symptoms:

  • Transmit is disabled on the web UI.

  • The screen does not show RDY.

Actions:

  • Press RESET to start the reset/arm sequence.

  • Wait for RDY (arm window). The window is short (about 2 seconds).

  • If RDY never appears, check for errors (see Error Labels).

ORE (Out-of-Range Resistance)

Symptoms:

  • Status label shows ORE.

  • Transmit does not start after pressing TRANSMIT.

Actions:

  • Verify transmitter and load connections.

  • Check that the minimum/maximum resistance limits are appropriate.

  • Press RESET and try transmit again.

ERR (Shared Error Line)

Symptoms:

  • Status label shows ERR.

Actions:

  • A safety/monitoring subsystem has asserted the shared error line.

  • Check the TX Log or error label on the screen.

  • Resolve the underlying error and press RESET.

Error Labels

Any error label returns the system to a safe wait state. Use the label to identify the source subsystem:

  • SM = Safety system

  • MM = Monitoring system

  • GM = Gate driver system

  • FM = Cooling/fan system

Common errors:

  • SM EMER: Emergency stop input active.

  • SM GIUV/GIOV: Global input under/over-voltage.

  • SM UDIUV/UDIOV: User-defined under/over-voltage limit.

  • MM OVP/OVN: Over-voltage (positive/negative).

  • MM OCP/OCN: Over-current (positive/negative).

  • GM OTMP: Gate driver over-temperature.

  • SM/MM/GM/FM LERR: Local error on that subsystem.

Wi-Fi Not Visible

Symptoms:

  • No ZT-100 SSID appears.

Actions:

  • On the front panel, open More Info and set Wi-Fi status to ON.

  • Wait for the Wi-Fi icon to appear on the top bar.

Can’t Open the Web UI

Symptoms:

  • Browser cannot reach the device page.

Actions:

  • If in hotspot mode, connect to the device SSID and open http://10.10.10.10/.

  • If in local network mode, use the IP address shown on the screen.

  • Confirm Wi-Fi status is ON.

Custom File Upload Fails

Symptoms:

  • Upload rejected or file not listed.

Actions:

  • Ensure the file extension is .usm.

  • The web UI rejects files larger than 256 KB.

  • Stay in Custom mode while uploading.

OTA Update Fails

Symptoms:

  • Upload rejected or target mismatch.

Actions:

  • Confirm the firmware file matches the selected target in the web UI.

  • If the upload is rejected, re-check target selection and file version.

  • Keep the browser open until the update process completes.