ijpds formats.book - Kodak

Chapter 4. Record Formats
Set Resolution Multiplier (SRM)
Set Resolution Multiplier (SRM)
The SRM record allows the data preparation program to specify distances
for character escapements and offsets, font escapements, spacing
values, and relative position values at a resolution higher than that of the
RIP.
This record sets a logical resolution for the current RIP and must appear
(if used) with the PHR and FAR records before any font records, fixed file
records, or the first document. The logical resolution is determined by
multiplying the resolution multiplier times the physical resolution of the
RIP. The resolution multiplier is calculated by raising 2 to the power of the
value in the exponent field of this record.
For example, if the exponent field contains 03, the resolution multiplier is
8 (2 to the third power). Assuming a physical resolution of 240 dpi for the
RIP, the logical resolution is 8 x 240 = 1920 dpi.
Assume that a distance field in one of the affected records contains a
logical X or Y distance of binary 101110100101 (2981 dots) and the
exponent field contains 3. The logical distance is converted to the
physical resolution of the RIP by moving the “binary” point 3 places to the
left, resulting in 101110100.101. The cursor is moved 372 dots according
to the whole binary number 101110100, but the fractional binary number.
101 is carried and added to the next fraction received. When the
accumulated fractions add up to a whole dot, the cursor is moved an extra
dot position.
Note: The controller may use data provided in this record to formulate a
printhead ID, solely or in conjunction with JC2, RIP, and PHR records.
Byte Position Bytes Field Name Description
1-2 2 Record Length The length of this record, in binary, including the record length
field. For example, hex 00 05 specifies a record length of 5 bytes.
3 1 Cyclic Record Count A binary cyclic record count using modulo 256. Each record in the
job is counted, starting with hex 01 for the first record. The 255th
record is hex FF and the 256th record is hex 00. This count is used
to verify record sequence.
4 1 Control Code A binary code that identifies the record type. A value of hex 39
identifies the SRM record.
5 1 Resolution Exponent A binary value with a range of 1-16. The resolution multiplier is
determined by raising 2 to the power of the value in this field.
The SRM record applies to the following fields in the following records:
SFM and FDM X and Y escapements
CDM and CCD X and Y offsets and escapements
SFS X and Y line spacing
X and Y character spacing
SRP X and Y
Reference Guide 4 - 11