The first thing to consider is whether you should update the RTP. Some updates to the service require the service and/or the scanner program to be updated as well, so you should take a whole-system approach to updates. Read the release notes for more information.
If you do decide to update the RTP, the latest V2.3x version is always available from this URL:
https://www.asp.com.au/downloads/aspluris/server/v2.3.0/abm/abmrtp.exe
