Soracom Onyx LTE™ USB Modem

Troubleshooting

If you encounter issues while using the Soracom Onyx LTE™ USB Modem, this page provides guidance on how to troubleshoot common problems. By following these steps, you can quickly identify and resolve issues to maintain a stable connection.

Common Connectivity Issues

The Onyx modem is connected but no data is being sent

If the Onyx modem is connected but not transmitting data, the problem may be related to the host's network configuration, or incorrect or missing APN settings.

• Host Network Configuration: Ensure the host device has the correct network configuration. If you have been following this guide and are using NetworkManager, check your connection settings using the nmcli con show soracom command. If you are using WvDial, check the /etc/wvdial.conf file to ensure the correct settings are configured as outlined in the Manual Installation sections.
• APN Settings: Ensure the APN settings are correctly configured. If you have been following this guide, review the Manual Installation section for the NetworkManager or WvDial for commands to configure the APN. You can also check and set the APN using AT commands for the Quectel EG25-G modem. To check the current APN, use the command AT+CGDCONT?. To set the APN for use with Soracom SIMs and services, use AT+CGDCONT=1,"IP","soracom.io", replacing "soracom.io" with the appropriate APN if a third-party SIM is being used.

The Onyx modem takes a long time to connect to a network

The time it takes the Onyx modem to connect to the network can be impacted by a variety of factors:

• Initial Network Scan: The Onyx modem may take longer to scan for available networks the first time you connect or if you've moved to a new location. This is normal behavior.
• Signal Quality: Suboptimal signal quality can significantly impact connection times. Check signal quality using the AT+CSQ command. The command returns an Received Signal Strength Indicator (RSSI) value as an integer from 0 to 31. A value of 0 means no signal, and 31 is the strongest possible signal. Sometimes, a value of 99 is also possible, indicating that the signal strength is not known or is undetectable. If the returned RSSI is below 14, try moving the Onyx modem to a different location with better signal quality. Additionally, if using external antennas, ensure they are correctly connected and positioned for optimal signal reception.

The Onyx modem is not detected by the host device

If your host device does not detect the Onyx modem, review the following steps:

• USB Connection: Check the USB connection and ensure the Onyx modem is securely plugged into the USB port. If the problem persists, try connecting the Onyx modem to a different USB port.
• Insufficient Power: Some ports may not provide sufficient power or may have connection issues. Plug the Onyx modem into a USB 3.0 port to ensure it receives sufficient power even under high load. If your device only supports USB 2.0, using a powered USB hub can ensure the Onyx modem receives enough power.
• Kernel Messages: For further diagnostics, check the kernel messages for any USB device errors using dmesg | grep USB. This can provide insights into potential issues or conflicts that might be preventing the Onyx modem from being recognized.

The Onyx modem performs a full network scan on every reboot

A bug exists in older versions of ModemManager (the NetworkManager component that detects and controls modems). This bug causes some Quectel modems—including the Quectel EG25-G used in the Onyx—to perform a full cellular network scan every time the Linux device reboots, whenever the modem is unplugged and reconnected, or when ModemManager restarts. While that scan is in progress, the modem cannot send or receive any data.

Once the modem has finished the network scan, the device and modem will resume normal operation. However, if your Linux device is restarted frequently, or your application requires periodically disabling and re-enabling the modem or restarting ModemManager, the network scan caused by the bug may introduce unacceptable delays in establishing cellular connectivity.

To see if your device is affected, run the mmcli --version command and check if you are running v1.14.0 or later. If you have an older version, you may need to update ModemManager.

In particular, the previous version of Raspberry Pi OS (such as Buster) has not updated its ModemManager package since v1.10.0. However, newer versions of ModemManager are available from the Debian Backports repository. To manually install the latest version of ModemManager, run the following commands to add the Debian Backports repository, update the package list, and install a newer version of ModemManager:

echo "deb http://deb.debian.org/debian buster-backports main" | sudo tee -a /etc/apt/sources.list
wget http://deb.debian.org/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2021.1.1_all.deb
sudo dpkg -i debian-archive-keyring_2021.1.1_all.deb
sudo apt-get update
sudo apt-get install -t buster-backports modemmanager

Once installed, repeat the mmcli --version command to check that your ModemManager has been updated. If the version is v1.14.0 or later, the bug should be resolved and the Onyx modem will no longer perform a full network scan on every reboot.

Additional Resources & Support

For further device and advanced troubleshooting steps, see our Troubleshooting guide.

For additional technical and product information, visit the Soracom Onyx LTE™ USB Modem page.

For complete information on using the Soracom User Console, SIM Management tools and APIs, Soracom platform services, and additional capabilities, documentation is available on the Soracom Developers website.