ijpds formats.book - Kodak

Record Information
Chapter 4. Record Formats
An IJPDS job file consists of variable-length, special-purpose records that
describe the printing job. Each record is identified by a control code. All
information needed by the printing system for the job is contained in the
job file.
This chapter describes each record in detail. The record descriptions are
presented in the sequence that the records might appear in the file. The
sequence of some records is fixed while the sequence of other records
can vary depending on the job requirements. Required record sequences
are discussed in Chapter 5.
Tables containing reference lists of all IJPDS records are contained in
Appendix A. Table A.1 provides a list of all records in alphabetic order by
name. The table provides the assigned control code and purpose of each
record along with a page reference to the record description in this
chapter. Table A.2 provides the same information in a list compiled in
numeric order by control code.
Records having a defined length may have pad bytes added at the end
and the extra bytes will be ignored. The extra bytes must be included in
the Record Length field. Defined length records are those where the
length of usable information is either fixed or can be determined by
examining fields in the record. A RIP record is an example of a record
where the length of the usable information is fixed (the length is always 5
bytes). A PHR record is an example of a record where a field in the record
can be examined to determine the usable length. The “Number of
Printheads” field can be used to determine the usable length (the length is
18 bytes for one printhead and 42 bytes for four printheads).
For records that contain binary fields with more than one byte, the
leftmost byte is the most significant. If a field occupies bytes 5 and 6 in a
record, byte 5 is the most significant byte. For example, hex 01 7F
specifies a value of 383.
Some records use 4-byte signed binary values in the two's complement
form to specify X and Y escapements and offsets. The maximum negative
value for these fields is shown in the following equation in both decimal
and hex representation.
-2 31 = -2,147,483,648 = hex 80 00 00 00
The maximum positive value for these fields is shown in the following
equation in both decimal and hex representation.
2 31 - 1 = +2,147,483,647 = hex 7F FF FF FF
Reference Guide 4 - 1