Xerox 3270 用户手册

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3270 Programmer’s Guide
Function Selection via the Line
- 15 -
NOTE:
In command strings in hex pair notation, only the
hexadecimal characters 0-9 and A-F are allowed. The
specifying of any other character may give unpredict-
able printing results.
Between the two leading and the trailing ESC characters all IBM
control codes, spaces, and the character "," will be ignored by the
converter. They may be inserted in command strings to facilitate the
reading of the datastream.
2.3. Apostrophe Notation
Another way of sending printer commands strings is to use the
apostrophe notation. Apostrophes tell the  converter that the
characters following should be regarded as ASCII characters in the
commands. Below you can see an example of this.
%%1B '\12'%
Structure of a command with the apostrophe notation
The above example shows the command code 1B (HEX) combined
with the apostrophe notation.
The apostrophe notation can only be used in connection with trans-
mission of characters in the LU3 character table. All IBM control
codes are ignored in command strings.
To ensure correct processing of the data, all spaces in the string
must be sent as the hexadecimal value (HEX 20). If e.g. you wish to
transmit "270 C/RS" the sequence should be sent as shown in the
following:
&&??%
Define temporary escape
         %%''270'20'C/RS'%
Syntax of a command with a blank sent in apostrophe notation