Wincor Nixdorf TH320, Руководство программиста

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TH320/TH420 Programmers Guide
103
User storage status
ASCII GS 0x97 m n
Hexadecimal 1D 97 m n
Decimal 29 151 m n
Value of m m specifies the type of stored object to be reported:
m = 0 return the kilo bytes (1024) of free user RAM,
n = 0 gets largest free block size
n = 1 gets the total size free
m = 3 return the CRC of a logo indexed by n
m = 5 return the CRC of a macro that has been stored, n = 0
For m = 0 the value of n selects are turn of either the largest free block or total free size, since
contiguous allocation cannot be assumed as this area is completely under user control through
address parameters.
n = 0
if only one instance of an object type is allowed (macro, user data, user defined characters).
n is the item index when more than one object of type m is possible.
n <= FE, see the comments about logo and character set indexes
n = FF : return a list describe in gall the existing items of type m
Note
When a specific item request is made, a returned CRC value of 0 0 indicates that no item is stored at
that index. There is a practically negligible possibility that a valid object will have a 0 0 CRC; if this is of
concern, applications should check the object downloaded byte sequence to verify that this is not the
case (as well as store the CRC as an “ID ” for the object if needed later for return value comparisons).
Downloaded character sets are identified by integer extending the existing codepage selection as
enumerated in the select international character set (= select character code table) command. The
firmware standard list is incrementally extended each time a new single or double byte set is
downloaded.
Single byte downloaded fonts are selected by m = 3 and 0x40 <= n < 0x80.
Since there are only three double-byte character sets supported, the value 0x80 / 0xA0 / 0xC0 selects
the first, second, third downloaded double byte font respectively. In return, each downloaded double
byte character band is reported individually as 0xC0, 0xC1, 0xC2 ….for as many bands as have been
defined.
This command returns the state of occupancy of available flash storage and user RAM. The printer
response for each item is a 4 byte header, 0x1D 0x97 nL nH (number of bytes that follow in the
response) and for each item a 4 byte structure: 1
st
m (type) byte, 2
nd
n index byte followed by a 2 byte
CRC in Lo Hi order of the data string in that storage space.
The return for m = 0–2 is the header and one 4-byte item giving remaining storage space in the CRC
position in Lo Hi order: 1D 97 4 0 m 0 fL fH, where f is the kBytes of storage remaining. Note that RAM
storage space is not content typed, while available flash is statically divided into logo, character set,
and user data types. Change of the divisions is possible via flash erasure and flash allocation
commands.
If the communication protocol is RS-232c – Xon/Xoff, then “X symbol substitution response” should be
configured with the setting communications parameters command (US STX , 1F 02).