FTAM/9000 Programmer's Guide

Chapter 11 433
Document Types and Constraint Sets
Document Types
If the class parameter is not present, the default is
FT_CL_GENERAL_STRING. The character strings may contain
characters from any of the characters sets registered for use as C0,
C1, G0, G1, G2, or G3 sets, including SPACE.
1
Refer to the
“Character Sets” chapter for this list of characters.
• The string_length parameter determines the length of maximum
number of octets in each data element. HP–UX responders accept an
unlimited string_length. If string_length is not present, the character
strings have a maximum length of 6144.
• The string_significance parameter determines the exact significance
of the character strings. Three values are supported:
• FT_SS_NO_SIGNIFICANCE String (data element) boundaries
are not preserved across transfers. For example, if you create a file
using eight strings, you may or may not receive eight strings back
when you read the file. Different FTAM implementations may
break the file into strings in different ways.
• FT_SS_FIXED String (data element) boundaries are preserved
across transfers, and each string is of the size specified in the
maximum string length parameter.
• FT_SS_VARIABLE. String (data element) boundaries are
preserved across transfers, and the length of each string is less
than—or equal to—the size specified in the maximum string
length parameter.
FTAM-2 Document Type
FTAM-2 contains zero or more FADUs, each of which contains zero or
more text strings. For FTAM-2, you can have any number of FADUs and
any amount of data (Figure 11-3). The data units are distinct. For
example, if you send five data units and ask for them back, you will
receive five distinct data units in return.
1. Registered in the International Register of Coded Characters Sets
for use with Escape Sequences