Cobos Device Server troubleshooting and recovery

What methods can I use to troubleshoot my Lantronix Device Sever running the CoBos OS?


1. Troubleshooting: Serial access to Setup Mode

Use terminal emulation software (HyperTerminal or TeraTerm) on the Device Server serial interface to enter the Setup Mode.  This procedure is also explained in the product User Guide available on this page: http://www.lantronix.com/support/documentation.html in the section "Configuration via Telnet or Serial Port (Setup Mode)"

Note (1): for embedded modules using serial signals at 3.3V CMOS logic level you must interface an RS232 serial transceiver to connect from your PC RS232 serial interface. We supply demo boards for our modules with RS-232 transceiver and DB9 serial connector for this purpose. Please check your Lantronix module product page for corresponding demo board Part Number: http://www.lantronix.com/device-networking/embedded-device-servers/.  

Warning: If you connect an RS232 serial port (e.g. the Com Port of a PC) directly to the serial interface of a Lantronix Embedded Device Server such as the XPort, you will very likely permanently damage the Device Server.

This is not covered by the warranty, so proceed with caution.


1. Connect a console terminal or PC running a terminal emulation program to your unit's serial port (if your Device Server has 2 serial interfaces please use the 1st serial interface). The default serial port settings are 9600 baud, 8 bits, no parity, 1-stop bit, no-flow control.

2. To enter Setup Mode, reset the unit, either by pushing the reset button, or cycling the unit's power (power off and back on). The self-test will begin. You have one second to enter three lowercase x characters (xxx). The easiest way to enter Setup Mode is to hold down the x key at the terminal (or emulation) while resetting the unit.

If you can enter the Setup Mode, set factory default first by choosing Defaults setup menu option, You also need to manually reset the network settings in the "Server" setup menu option and in case of a wireless device the "WLAN" setup menu option as these are not changed with the "Defaults" setup menu.

then configure your settings as required, then select the "Save and exit" menu option to save and exit the Setup Mode.

3. Then test communications to your serial device. (This assumes that the proper cabling was in place and working prior to your issue, requiring you to troubleshoot.)


2. Device Installer firmware recovery option

If the above troubleshooting procedure is not successful or you are unable to access the configuration menu using the serial access method in step one, please try this firmware recovery procedure.

 Warning: This recovery method is intended to be used as a last resort if all other methods of loading firmware onto your device server have failed.

There is no mechanism to check that you are loading the correct file. If you load the wrong file it can destroy the firmware image in the device server's flash memory. There is no method to recover from this in the field.

Loading the wrong file through the serial port is not covered by the warranty. Proceed with caution.

This procedure requires the Lantronix Device Installer software.  You can download the latest version here:
Latest version of DeviceInstaller

1. Connect your Device Server to the serial port of your PC and open the Device Installer program.
(If you try to recover an embedded module please see "Note (1)" above)

2. In Device Installer application, go into "Tools" menu, then "Advanced" and click on "Recover Firmware" (or press Function Key F8).

3. Select the PC com port, the Device Server model, and the ".rom" firmware file.  You can download the latest firmware version here:
http://www.lantronix.com/support/downloads.html 

4. Click OK and restart the Device Server. After 1 to 2 minutes the firmware recovery will complete. Check your configuration following the method in item 2 of the Troubleshooting section above.

5. (Optional) You may need to reload Device Server web Manager (.cob file). This is described in the following FAQ:
Using DeviceInstaller to upgrade Firmware and Web manager


If you are unable to access the Device Server or communications still fail after step one troubleshooting or, step two, the serial firmware recovery process, you will need to call Lantronix Tech Support for your location.  A tech support rep will further assist you to troubleshoot the Device Server and will issue an RMA request if the unit is still under warranty and not recoverable.

For local support in your language, please fill out the "Locate a Partner" form ( http://www.lantronix.com/buy/ ) for referral to a local Lantronix office or distributor who can supply support.



[Originally Published On: 04/06/2010 03:39 PM]