L-VIS User Manual
115
LOYTEC
Version 6.2
LOYTEC electronics GmbH
NOTE:
Assign good names to your trend control objects, to make it easy to identify the data files
and relate them to the trends which are visible on the device. Consider to add the name of
each trend to the page where the trend is shown, so that the user is able to clearly identify
each control and its data file.
If the trend control object name contains non-ASCII characters, the resulting file name will
be encoded in ISO-10646 (Unicode) and will be transferred to the client in UTF-8
encoding, according to the FTP protocol extension RFC2640. Clients who support this
extension can then display these file names correctly. Most web-browser based FTP clients
either detect the UTF-8 encoding automatically or provide an option where the user may set
the desired encoding. To maximize compatibility to existing FTP clients, it is desirable to
use only ASCII characters for the name of trend control objects.
An easy way to manually access the files on the device is to use the windows explorer or a
web browser and type the following into the address/URL field:
ftp::<user>@<address>/
Replace <user> with either operator or admin and <address> with the IP address or DNS
name of the device, for example:
ftp::[email protected]/
You will then be asked for the password and the file system contents will be shown. You
can now navigate to the required files and download them to the local hard disk of your PC
for further processing.
NOTE:
Since the trend data files are actually symbolic links to a device driver, you cannot directly
open the files on the device. Also, the file size may be shown as 0, because it is not
immediately known (the data is generated on the fly, while you are downloading it). You
may only download the files. Some FTP client software is known to have problems
processing symbolic links to files. They tend to display these files as being directories but
any attempt to open this directory will fail, since it really is a file. Examples for such
programs are FileZilla and Leech-FTP. If you encounter this problem with your FTP client,
use another client or fall back to the windows explorer or the command line FTP client
(which is known to work as well). If your device supports secure connections, programs like
WinSCP may also be used as an alternative to FTP clients. The SCP protocol uses only one
port and is therefore easier to handle in environments where NAT routers and firewalls are
present.
9.5.6.5 Operating Trend Controls
Trend controls do not allow data input, but they can be made selectable. If the control is
selectable, touching it on the screen will display a vertical line at the touch point and open a
cursor box, showing the exact data which was recorded for the selected point in time.
NOTE:
In case the navigation buttons are hidden, the first touch will show the navigation buttons
only and a second touch is necessary to show the data cursor.
The cursor box will show the absolute date and time of the current cursor position, as well
as the current value at that time for each of the curves displayed. Each value is printed in
the same color as the corresponding curve, to relate the displayed numbers with the curves.
If a curve has a label configured, the label text is shown in front of the value.
