NCR RealScan 7802, Руководство пользователя

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NCR RealScan 7802 Price Verifier User Guide
497-0425530 Release E 06/03 43 of 94
Response
[ length ][ DIFF ][ Bool ]
Bool value is TRUE if the file's date/time are DIFFERENT than the provided
timestamp and FALSE if it is the same.
Response
[ length ][ ERRR ]
Requested file does not exist or request is malformed. Explanatory message is
optional, should be string consisting of number, white space, and optional text.
[filespec] uses UNIX style forward-slash directory notation. It is the responsibility of the
server to convert the notation to the native method, and to guarantee that the path
cannot extend outside of the default directory.
The directory '/' refers to the current directory; a leading '/' is ignored. The QFX server
must guarantee the requested file is in or below its current directory.
Line-terminators are new-line characters; carriage returns are optional.
The server is responsible to read text files and transmit them with appropriate line
breaks. Specifically, this applies to VAX/VMS.
Using Graphics Characters
RealScan 7802 with an AMLCD can display graphics characters such as Kanji and
Chinese (ideograms) as well as standard Roman text characters. The graphics font file is
downloaded into the price verifier at boot up time by a command line in the realscan.ini
file. As only one font file can be stored at a time, the display is limited to the characters
in the loaded font set. Certain fonts contain other characters; for example the Kanji font
set also contains English, Greek and Cyrillic characters.
Displaying graphics characters requires two hex bytes (double-byte text) per character
be sent due to the large number of glyphs in the font set (Kanji has 7,640 characters).
RealScan 7802 can send text in either single byte or double byte modes. The rules for
using double byte text are shown here.
Double byte text strings come in two types, Big-Endian and Little-Endian. The server
hardware determines if you will need big endian or little endian strings. Double byte
strings sent in trivial mode must be double NUL (00 00) terminated whereas strings sent
in nominal mode do not have to be.
Big-Endian text strings start with the bytes FE FF and end with the bytes 00 00.
Ex: FE FF b
1
b
2
b
3
b
4
b
5
b
6
b
7
b
8
b
9
b
10………..
00 00
Little-Endian text strings start with the bytes FF FE and end with the bytes 00 00
Ex: FF FE b
1
b
2
b
3
b
4
b
5
b
6
b
7
b
8
b
9
b
10………..
00 00
where b
1
-b
10
are a string of 5 double-byte character codes.
In realscan.ini, double byte strings can be used for wallpaper but the text must start with
<< instead of < or // instead of /.