Special characters used with line data

There are two types of special characters that can be used with line data; carriage control characters (CC) and table reference characters (TRC).

Carriage control characters affect the data's line positioning. A carriage control character can be represented as either American National Standards Institute (ANSI) or machine code. You cannot use both ANSI and machine codes within a single data set. ANSI carriage control is a standard representation that is used with printers from many different manufacturers. See the ANSI carriage control characters topic for the ANSI codes and their functions. Machine code control characters were defined by IBM®; they correspond to channel command words issued by the operating system. See the Machine carriage control characters topic for the IBM machine code values and functions.

There are differences in the conventions used by the i5/OS™ operating system for ANSI and machine code line spacing. The i5/OS convention for ANSI handles line spacing and then causes the line to be printed. The i5/OS convention for machine codes causes the line to be printed and then performs the spacing action.

Table reference characters allow an additional byte at the beginning of a line. The byte indicates which coded font (specified on the AFPCHARS parameter) is used to print the line. Up to four coded fonts are specified on the AFPCHARS parameter. The table reference character contains a value of X'F0', X'F1', X'F2', or X'F3'. The value corresponds to the relative position of the required coded font in the list on the AFPCHARS parameter. If table reference characters are used, every data record must contain a table reference character. The printer file parameter Table Reference Characters (TBLREFCHR) specifies whether table reference characters are in the data.

If carriage control and table reference characters are used with the data, the table reference character follows the carriage control character. Both special characters precede the data. If carriage control bytes are not used, the table reference character is the first byte of the data record.

These graphics illustrate the valid forms of line data.

Figure 4. Simple line data

This figure has one box with data in it.

Figure 5. Line data with table reference characters

This figure has two boxes. The first has a table reference character (TRC) and the second has data in it.

Figure 6. Line data with carriage control characters

This figure has two boxes. The first has a carriage control character (CC) and the second has data in it.

Figure 7. Line data with carriage control characters and table reference characters

This figure has three boxes. The first has a carriage control character (CC), the second has a table reference character (TRC), and the third has data in it.

Related reference

ANSI carriage control characters

Machine code carriage control characters