Keithley 6430, Instruction Manual

Page: 149 / 558

Range, Digits, Speed, and Filters 6-11
From the above equation, it can be seen that the minimum number of sample readings is 1
(n=0) and the maximum number is 11 (n=5). The following table shows the number of sample
readings for each rank setting.
The first-in, first-out stack for the Median Filter operates as a moving type after it fills. For
example, if the Median Filter is configured to sample 11 readings (Rank 5) as shown in
Figure 6-4, the first filtered reading will be calculated (and displayed) after 11 readings are
acquired and placed in its filter stack. Each subsequent reading will then be added to the stack
(oldest reading discarded) and another Median Filter reading will be calculated and displayed.
NOTE
With auto range enabled, a range change cannot occur until a reading is yielded by
the median filter process. Therefore, auto ranging could be very slow when the
median filter is enabled.
NOTE
If the Repeat Filter is enabled, the Median Filter operation will not start until after
the Repeat Filter operation yields a reading. In other words, after a Repeat Filter
reading is yielded, that reading will then be sent to the Median Filter stack.
Rank
setting
# of Sample
readings
0
1
2
3
4
5 1
3
5
7
9
11
Reading #11
#10
#9
#8
#7
#6
#5
#4
#3
#2
Reading #1
•
•
•
Median
Reading
#1
Reading #12
#11
#10
#9
#8
#7
#6
#5
#4
#3
Reading #2
•
•
•
Median
Reading
#2
Reading #13
#12
#11
#10
#9
#8
#7
#6
#5
#4
Reading #3
•
•
•
Median
Reading
#3
Figure 6-4
Median filter
(rank 5)