276
Chapter 5
Measurement Definition
Measurement Parameter Definition
are performed by the “
hpe5022_writetrackOffsetCompPattern” function.
The burst pattern is defined by a write offset, an aperture time and a pattern frequency.
These three parameters can be set by users. Also, the function allows you to set these
parameters automatically. In auto mode, the offset is set at the half of write track width.
The aperture time is set at 2
×
10
-3
second, however, if an aperture time of 2
×
10
-3
second
exceed a half of the track, the aperture time set at a half of the track. The pattern frequency
is set at the peak of roll off measurement result. See the
“hpe5022_trackOffsetCompPatternAuto” function in the programming manual in detail.
Figure 5-30
Write Burst Pattern Sequence
The burst pattern position is able to have a offset from the track center. The
“hpe5022_trackOffsetCompPatternPosition” function defines the offset position. This
function allows you that the head position stays at not only the track center but also a
certain offset position from the track center.
Figure 5-31
Burst Pattern Position
Writing a data pattern should be executed just after the burst pattern is written. In other
words, the function including a write sequence, such as
hpe5022_measureTrackProfile(hpe5022_SEQ_ER_WR_M or hpe5022_SEQ_WR_M)
function, should be executed just after the “hpe5022_writetrackOffsetCompPattern” is
executed. Because there might be some drift between the data pattern and the burst pattern
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
