XL4 Plus RTU – How to update firmware

Updating the Q04 Plus firmware in an XL4 Plus RTU is via USB. Please read the XL4 Plus RTU User manual before starting the process below:

Equipment required:

  • XL4 Plus RTU
  • DC Power supply
  • USB cable (Type A-B)
  • USB drive (formatted as FAT 32) containing both the Q04 Plus Application firmware file (.elf) and the MD5 validation file (.md5) at the root level of the USB drive. The .elf and .md5 files are distributed by QTech.
1Disconnect power from the RTUAlso disconnect all the I/O and communication devices from the RTU.  
2Insert the USB drive  USB drive must contain the .elf and md5 files at the root level.  
3Power up the RTUThe RTU will detect the USB drive and automatically load the new firmware. Do not remove power from the RTU during this programming process.  
4Watch the status LEDsThe status LEDs will flash in sequence to indicate programming is in progress.  
5Wait until the OK indicator LED slow flashesThis indicates the firmware update is now complete.  
6Remove the USB driveImportant. Do not leave the USB drive in the socket after upgrading is complete. Otherwise, the next time the RTU reboots it will reload the new firmware again.

Please get in touch with us if you are upgrading from an XL4 to XL4 Plus RTU. This is a more involved process defined in this application note.