Campbell Scientific CR7 Measurement and Control System - Manual (Page 116)

SECTION 11. OUTPUT PROCESSING INSTRUCTIONS
11-4
the total number of scans. This form of output
is also referred to as a frequency distribution.
The weighted value histogram uses data from
two input locations. One location contains the
bin select value; the other contains the weighted
value. Each time the instruction is executed,
the weighted value is added to a bin. The sub-
range that the bin select value is in determines
the bin to which the weighted value is added.
When the Output Flag is set, the value
accumulated in each bin is divided by the
TOTAL number of input scans to obtain the
values that are output to Final Storage. These
values are the contributions of the sub-ranges
to the overall weighted value. To obtain the
average of the weighted values that occurred
while the bin select value was within a particular
sub-range, the value output to Final Storage
must be divided by the fraction of time that the
bin select value was within that particular sub-
range (i.e., a standard histogram of the bin
select value must also be output).
For either histogram, the user must specify: 1)
the number of repetitions, 2) the number of
bins, 3) a form code specifying whether a
closed or open form histogram is desired (see
below), 4) the bin select value input location, 5)
the weighted value input location (see below),
6) the lower range limit, and 7) the upper range
limit.
The standard histogram (frequency distribution)
is specified by entering "0" in the weighted value
input location parameter. Otherwise, this
parameter specifies the input location of the
weighted value. With more than one repetition
the bin select value location will be incremented
each repetition and the weighted value location
will remain the same (same weighted value
sorted on the basis of different bin select
values). The weighted value location will be
incremented if it is entered as an indexed
location (key "C" at some point while keying in
Parameter 5; two dashes, --, will appear on the
right of the display).
At the user's option, the histogram may be
either closed or open. The open form includes
all values below the lower range limit in the first
bin and all values above the upper range limit in
the last bin. The closed form excludes any
values falling outside of the histogram range.
The difference between the closed and open
form is shown in the following example for
temperature values:
Lower range limit 10 oC
Upper range limit 30 oC
Number of bins 10
Closed Form Open Form
Range of first bin 10 to 11.99o <12o
Range of last bin 28 to 29.99o >28o
A common use of a closed form weighted value
histogram is the wind speed rose. Wind speed
values (the weighted value input) are
accumulated into corresponding direction
sectors (bin select input).
PAR. DATA
NO. TYPE DESCRIPTION
01: 2 Repetitions
02: 4 Number of bins
03: 2 Form code (0=open form,
1=closed form)
04: 4 Bin select value input location no.
05: 4 Weighted value input location no.
(0 = frequency distribution option)
06: FP Lower limit of range
07: FP Upper limit of range
Outputs generated: number of bins * repetitions
*** 77 RECORD REAL TIME ***
FUNCTION
This instruction stores the current time in Final
Storage. At midnight the clock rolls over from
23:59 to 00:00. The day also changes.
If hourly or daily summary data is output, it may
be desirable to have the previous day specified
with the output, since that is when the
measurements were made. Entering a 2 for the
day code causes the previous day to be output
if it is the first minute of the day. Similarly,
entering 2 for the hour-minute code causes
2400 instead of 0000 to be output (the next
minute is still 0001). When day and hour-
minute are both output, a 2 for either code
results in the previous day at 2400.