HP 1650B Programming Reference Manual page 90

DATA
Note
System Commands
6-16
In the Transitional timing mode the logic analyzer
Information Bytes.
performs the following steps to obtain the information bytes:
1. Four samples of data are taken at
stored and the value of the last sample is retained.
2. Four more samples of data are taken. If any of these four samples differ
from the last sample of the step 1, then these four samples are stored
and the last value is once again retained.
3. If all four samples of step 2 are the same as the last sample taken in step
1, then no data is stored. Instead, a counter is incremented. This
process will continue until a group of four samples is found which
differs from the retained sample. At this time, the count wiIl be stored
in the memory, the counters reset, the current data stored, and the last
sample of the four once again retained for comparison.
The stored count indicates the number of 40 ns intervals that have elapsed
between the old data and the new data.
The rows of the acquisition data may, therefore, be either four rows of
data followed by four more rows of data, or four rows of data followed by
four rows of count. Rows of count will always be followed by four rows of
data except for the last row, which may be either data or count.
nanosecond intervals. The data is
10
HP 1650B/HP 16518
Programming Reference