There are 2 ways to do this-
Obtain the latest RTB file from Acuity Brands Controls Technical Support
Save the file in a folder you can reference
Connect to the Synergy Controller and find it
Click on the lighting bolt tab in Config and it will prompt you to find the file
Go to the folder where you have the RTB file stored and click on it.
The firmware will download
Open Hyperterminal in wndows, choose a com port
click on transfer choose send file
get file, choose the latest file
type "bootdisk" then space then the file name that you just uploaded.