Echelon FTXL - Manual (Page 204)

192 Downloading an FTXL Application Over the Network
Overview
For a Neuron-hosted device, you can update the application image over the
network using LNS or another network management tool. However, you cannot
use the same tools or technique to update an FTXL application image over the
network. Many FTXL devices do not require application updates over the
network, but for those that do, this appendix describes considerations for adding
this capability to the device.
If an FTXL device has sufficient non-volatile memory, it can hold two (or more)
application images: one image for the currently running application, and the
other image to control downloaded updates to the application. The device then
switches between these images as necessary. Because neither the FTXL LonTalk
API nor the FTXL LonTalk protocol stack directly supports updating the FTXL
application over the network, you must:
1. Define a custom application download protocol.
2. Implement an application download utility.
3. Implement application download capability within your FTXL
application.
For the application download process:
• The application must be running and configured for the duration of the
download.
• There must be sufficient volatile and non-volatile memory to store the
new image without affecting the current image.
• The application must be able to boot the new image at the end of the
download. During this critical period, the application must be able to
tolerate device resets and boot either the old application image or the new
one, as appropriate.
This appendix decribes some of the considerations for designing an FTXL
application download function. For additional considerations, see the Altera
application note AN 429: Remote Configuration Over Ethernet with the Nios II
Processor .
Important: This appendix does not describe how to download updates to the
firmware image into the FTXL 3190 Free Topology Smart Transceiver. It only
describes updates to the application image running on the host processor.
Custom Application Download Protocol
The custom FTXL application protocol that you define for downloading an FTXL
application over the network should support the following steps:
1. Prepare for application download.
When the application download utility informs the current FTXL
application that it needs to start an application download, the application
should respond by indicating whether it is ready for the utility to begin
the download. The utility must be able to wait until the application is
ready, or abort download preparation after a timeout period. The utility