Printek FormsMaster 8000, Руководство программиста

Страница: 25 / 150

19
EPSON FX EMULATION
Introduction
This section describes the control codes and escape sequences comprising Epson FX emulation. This
emulation may be selected by setting “Emulation” to “Epson” in the interface setup menu, or via
software with the
ESC ESC 2 sequence. While this emulation is selected, control codes and escape
sequences from other emulations are not available.
Control codes and escape sequences are used to control printer operation. An ASCII control code is a
single character in the range 00 hex through 1F hex, and 7F hex. The
ESC (Escape) control code (1B
hex) is used to introduce character strings called escape sequences, which provide an extension of the
commands available with ASCII control codes.
Some escape sequences accept one or more numeric parameters. If a sequence accepts one numeric
parameter, it will be represented as “
n ”. If a sequence accepts more than one numeric parameter, they
will be represented as “ n1 n2 ... nx ”.
Since numeric parameters are always encoded in one byte, their values may range from 0 to 255
decimal. Please note that the value will never be represented by a string of ASCII decimal digits (“0”
through “9”). For example, a value of 66 decimal would be sent as a single byte with a hex value of
42. This is equivalent to sending the ASCII character “B”. It is entirely different than sending the two
printable ASCII characters “66”.
If a numeric parameter is limited to a value of zero or one, it may be sent as a single byte with a value
of 00 or 01 hex (NUL or SOH), or it may be sent as a single printable ASCII character “0” or “1” (30
or 31 hex).
Spaces are used when documenting escape sequences to increase readability. The spaces within the
sequences are for readability only; they are not part of the sequences themselves. Characters that
appear in
italics (such as “ n ” and “ n1 n2 ” above) are not sent to the printer as is; they are used as a
place holder indicating that some value must be supplied.
Multiple character strings without intervening spaces typically represent control codes. For example,
BS is the Backspace control code (08 hex), not the two characters “B” and “S” (42 and 53 hex). An
ASCII Control Code Table is contained in the appendices for your convenience. If you have any doubt
about how to interpret a documented control code or escape sequence, refer to the hex representation in
the provided example. This should clarify any ambiguity. The examples may also be helpful when
analyzing a hex dump (see Hex Dump chapter) printed by the printer.
Column and line numbers begin at zero, not at one. Keep this in mind when setting tabs, margins, etc.