Operator`s manual

8-1
SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES
The following examples are intended to illustrate the use of Processing and Program Control
Instructions, flags, and the capability to direct the results of Output Processing Instructions to Input
Storage.
The specific examples may not be as important as some of the techniques employed, for example:
Directing Output Processing to Input Storage is used in the Running Average and Rainfall Intensity
examples (8.1 and 8.2).
Flags tests are used in the Running Average, Interrupt Subroutine, and Converting Wind Direction
examples (8.1, 8.5, and 8.7)
Control ports and the Loop are illustrated in the AM416 example (8.3).
These examples are not complete programs to be taken verbatim. They need to be altered to fit specific
needs.
8.1 COMPUTATION OF RUNNING
AVERAGE
It is sometimes necessary to compute a running
average (i.e., the average includes a fixed
number of samples and is continuously updated
as new samples are taken). Because the output
interval is shorter than the averaging period,
Instruction 71 cannot be used; the algorithm for
computing this average must be programmed by
the user. The following example demonstrates a
program for computing a running average.
In this example, each time a new measurement
is made (in this case a thermocouple
temperature) an average is computed for the 10
most recent samples. This is done by saving all
10 temperatures in contiguous input locations
and using the Spatial Average Instruction (51) to
compute the average. The temperatures are
stored in locations 11 through 20. Each time the
table is executed, the new measurement is
stored in location 20 and the average is stored in
location 2. The Block Move Instruction (54) is
then used to move the temperatures from
locations 12 through 20 down by one location;
the oldest measurement (in location 11) is lost
when the temperature from location 12 is written
over it.
Input Location Labels:
1:Panl Temp 15:Temp i-5
2:10smpl av 16:Temp i-4
11:Temp i-9 17:Temp i-3
12:Temp i-8 18:Temp i-2
13:Temp i-7 19:Temp i-1
14:Temp i-6 20:Temp i
Where i is current reading,
i-1 is previous reading, etc.
* 1 Table 1 Programs
01: 10 Sec. Execution Interval
01: P17 Panel Temperature
01: 1 Loc [:Panl Temp]
02: P14 Thermocouple Temp (DIFF)
01: 1 Rep
02: 1 5 mV slow Range
03: 1 IN Chan
04: 1 Type T (Copper-Constantan)
05: 1 Ref Temp Loc Panl Temp
06: 20 Loc [:Temp i ]
07: 1 Mult
08: 0 Offset
03: P51 Spatial Average
01: 10 Swath
02: 11 First Loc Temp i-9
03: 2 Avg Loc [:10smpl av]