Flashing an xNode using a serial cable

Updated by Bryan Jones


This applies to all Telos or Axia branded xNodes;

  • 2001-00357-000: xSwitch Zero-Configuration Ethernet Switch for Livewire
  • 2001-00298-000: Telos Alliance Analog xNode
  • 2001-00299-000: Telos Alliance AES/EBU xNode
  • 2001-00300-000: Telos Alliance Mixed Signal xNode
  • 2001-00297-000: Telos Alliance Microphone xNode
  • 2001-00301-000: Telos Alliance GPIO xNode


A serial cable can be used for updating and programming an xNode by connecting to the internal serial port in the unit.

Connecting this serial cable requires removing the cover of the xNode and accessing it while the unit is connected to AC Power. If you are not familiar with, or are uncomfortable with these kinds of procedures, please contact support for other alternatives.

Connecting the Serial Cable

A custom serial cable that can connect to a small 3-pin header inside the xNode is required.  To access you will need to The cable you will need looks like this;

  1. Remove the cover from the xNode
  2. Connect the serial cable to the serial header (labeled CT4) inside the xNode and to an available serial port on your computer.

This picture shows the proper connection to the xNode.

  1. Using a Terminal Program (like Putty), connect to your serial port using the settings;
  • baud - 19200
  • parity - none
  • bits - 8
  • stop - 1
  • no flow control
  1. Power on the xNode
  2. Upon applying power, immediately start tapping the ESC key on your keyboard to obtain the "uMon>" micro monitor boot loader prompt. 
If you never get this uMon> prompt to appear, there is some larger hardware problem. If you DO get to the uMon prompt then you can proceed with re-flashing this node.

Gather software needed for flashing the xNode

You will need a couple of pieces of software;

Rename this file to flash.bin or something short.  Otherwise, in the next steps, you have to type this whole string.

Upload files to the xNode

Once connected by putty or other terminal program type the following commands. 

A word of warning. Type carefully. No backspace keys are allowed. If you mistype, you have to start over.
You will need to have this node and your computer connected by both serial and Ethernet. For this example, the computer has an IP of and we manually set the IP of the xNode to 
  1. uMON>set IPADD;ether off;ether on
  2. uMON>flash erase 4-130  
DO NOT erase any other memory segments. Erasing outside of this range will erase the operating system flash locations.
  1. uMON>tftp get flash.bin 0x20000
If everything is correct, you should see tftpd32 jump in to action and send the file.
  1. uMON>flash write 0xff040000 0x20000 0x003e0000
  2. uMON>reset

This will reboot the node. This time, let it boot and do not press ESC.

Set the MAC Address

  1. With the serial cable still connected and after reboot, from the prompt, type the command;
setmac aabbccddeeff
aabbccddeeff represents the mac address originally assigned to the xNode, by Telos, when it was built. The mac address can usually be found on a small white sticker on the inside of the unit or on the underside.

Perform any software updates and restore your configuration.

If there are no other hardware problems, you should be done.   If you get a menu back on the front of the node you know you are good.

You can use the normal procedures for updating beyond version 1.6.4e if so desired.

How did we do?