Below is a guide to upgrade the firmware on the RSC-HMU controller. The process takes about 5 mins to complete.
You may want to check the data card installed is compatible before updating the firmware; for the low cost you may want to install a new data card and copy from the old one before performing this procedure.
Then navigate to the configuration page:
Then go to update:
You can see the current firmware version where it says "Application Image:". RSC v0.53.6g+CX53-11" is the most current firmware. If it says this it does not require updating.
If the version is lower than this (0.51, 0.50) then you click the choose file button. Select the 0.53 firmware version (attached to this help article if you need a copy!) and click upload.
The firmware will then upload to the module and it will then ask you on this screen to reboot to install, or cancel.
Click reboot and the controller will reboot and install the firmware update.
Once done, please check the settings, but generally I have not had any issues with settings being lost, as they are on the data card. (see note above)