Dynapro Technologies Dynapro ET TCS, Application Developer'S Manual

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An ANSI standard control string is a remote command that consists of a special sequence of two
or more codes starting with the Escape code <ESC>, the Control Sequence Introducer code
<CSI>, or the Device Control String code <DCS>. Control strings provide the host with
commands that control the TCS.
The starting control code indicates to the TCS that it should interpret the next code as belonging
to a command. If the command is in the correct format, and is recognized, the TCS does a
specific function. If the command is in the correct format, but is not recognized, the TCS ignores
the command. If the command is not in the correct format, the TCS prints out the remainder of
the command, from the point where the format became incorrect.
All control strings supported by the TCS are summarized in Table 3-3, grouped by function.
Some of the control strings include optional numeric and selective parameters, which are
represented in Table 3-3 in angle brackets (for example, <Ps>). Numeric and selective
parameters are discussed more fully later in this chapter. The specific parameters for each
command are described in the detailed command descriptions in Chapter 5.
The control strings supported by the TCS can be grouped into three categories, according to their
composition:
•
Simple Escape sequences
•
Device Control Strings
•
Control sequences
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Simple Escape sequences can be sent by the host as described in Appendix B, and do not include
optional parameters. These control strings begin with the <ESC> code, followed by any code
other than [, possibly followed in turn by other codes. For example, the Index command consists
of the control string <ESC>D. All variations of these control strings are listed in Appendix B and
again in the detailed descriptions of the respective commands.
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Device Control Strings begin with the <DCS> code (or its equivalent escape sequence,
<ESC>P), and are terminated by the <ST> code (or its equivalent escape sequence, <ESC>\).
The TCS recognizes only one Device Control String, the Down-Line Load Character Font
command. For more information, refer to the description of this command in Chapter 5.