16. Downloading from the web server
bPrinciple
VW3A3310d Ethernet card | PC |
File system |
|
Write to |
|
Flash memory |
|
Read | FTP server |
| Internet |
| Explorer |
Read | HTTP server |
|
The Ethernet card has an embedded FTP server which authorizes access to the various URLs available for the HTTP server. A browser such as Internet Explorer can be used to display the URLs like a disk in the Windows explorer. This “disk” consists of various directories containing the URL files. It is therefore possible to use the different commands managed by Windows explorer such as deletion, renaming or writing (downloading) files (check that card IO Scanning has been disabled).
b File management
The memory zone assigned to the web server URLs consists of 24 blocks:
•23 sectors of 64 Kb for file storage.
•1 sector of 64 Kb for the file table.
The web server storage capacity is 1.5 Mb, i.e. 1536 Kb.
The file table is used to make the link between the HTTP server, the FTP server and the various “URL” files. This table is dynamic and is cleared and reprogrammed each time there is a change.
The maximum number of URL files is limited to 150.
The information relating to each file is as follows:
•File name (32 characters max.).
•Location address in the card memory.
•File size in bytes.
•“FTP” storage directory (html, html/lib/js etc.).
•URL processing function. (Access management, etc.). The URLs have a default function which requires a password (“HTTP password”) in order to access them via HTTP, apart from a few exceptions (see below).
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