Campbell Scientific CR510 Basic Datalogger - Manual (Page 126)

SECTION 10. PROCESSING INSTRUCTIONS
10-6
*** 58 LOW PASS FILTER ***
FUNCTION
Apply a numerical approximation to an analog
resistor capacitor (RC) low pass (LP) filter using
the following algorithm.
F(Xi) = W*Xi + F(Xi-1) * (1-W)
Where X = input sample, W = user entered
weighting function (O< W <1). If W=O,
F(Xi)=X
1
; if W=1, F(Xi)=X and F(Xi-1) = output
calculated for previous sample
The equivalent RC time constant is given by
T/W, where T is the sampling time in seconds.
For values of W less than 0.25, the analogous
"cut off" frequency (the frequency where the
ratio of output to input is .707) is accurately
represented by W/(2
π
T). For larger values of
W, this "analog" estimate of the cutoff frequency
becomes less representative.
On the first execution after compiling, F(X) is
set equal to X.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions [REPS]
02: 4 First input location for
input data
[X]
03: 4 Dest. input location for
first filtered result[F(X)
or Z]
04: FP Weighting function, W
[W]
Input locations altered: 1 per repetition
Intermediate locations required: 1 per repetition
*** 59 BRIDGE TRANSFORM ***
FUNCTION
This instruction is used to aid in the conversion
of a ratiometric Bridge measurement by
obtaining the value for R
s
which is equivalent to
R
f
[X/(1-X)], where X is the value derived by the
standard CR510 Bridge Measurement
Instructions (with appropriate multiplier and
offset, Section 13.5) and R
f
represents the
MULTIPLIER value. The result of Instruction 59
is stored in the same location that X was.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Repetitions [REPS]
02: 4 Starting input location
& result destination [X]
03: FP Multiplier (Rf) [MULT]
Input locations altered: 1 per repetition
*** 61 INDIRECT INDEXED MOVE ***
FUNCTION
Moves input data from location X to location Y,
where X and/or Y are indirectly addressed (X
and Y are stored in the locations specified by
Parameters 1 and 2). If a location parameter is
specified as “indexed” (xxxx--), then the actual
input location referenced is calculated by adding
the current index counter to the value in the
specified input location. When used outside a
loop, the addressing is simply indirect because
the index counter is zero.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 4 Input location
containing source
location X
02: 4 Input location
containing destination
location Y
Input locations altered: 1
*** 63 PARAMETER EXTENSION ***
Instruction 63 is used immediately following
Instructions 97 or 98 to allow the entry of a variable
number of parameters. Instruction 63 can be
entered several times in sequence if the number of
parameters requires it. There are 8 two digit
parameters. Refer to instruction being extended
(97, 98) for specifics on the use of Instruction 63.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01:-08: 2 Depends upon preceding
instruction. Following
Instruction 97 RF IDs
and Phone No. 1 digit at
a time, 32 Between RF
IDs, 70 after the last RF
ID, 32 and 84 Between
RF and DC112 Phone,