Campbell Scientific CR10X Measurement and Control System User Manual

Page 170

SECTION 10. PROCESSING INSTRUCTIONS

10-12

TABLE 10-2. Maximum Number of Outputs and Output Order for K Input Values.

(The output order flows from left to right and from top to bottom)

INPUTS:

.....

MAX NO.

OUTPUTS

TYPE

OUTPUTS

(1st)

(2nd)

(3rd)

(4th)

(Kth)

Means

M(X1)

M(X2)

M(X3)

M(X4)

.....

M(XK)

Variances

V(X1)

V(X2)

V(X3)

V(X4)

.....

V(XK)

Std. Deviation

SD(X1)

SD(X2)

SD(X3)

SD(X4)

.....

SD(XK)

Covariance

(K/2)(K-1)

CV(X1,X2)

CV(X1,X3)

CV(X1,X4)

.....

CV(X1,XK)

CV(X2,X3)

CV(X2,X4)

.....

CV(X2,XK)

CV(X3,X4)

.....

CV(X3,XK)

...

.
CV(XK-1,XK)

Correlation

(K/2)(K-1)

CR(X1,X2)

CR(X1,X3)

CR(X1,X4)

.....

CR(X1,XK)

Coefficient

CR(X2,X3)

CR(X2,X4)

.....

CR(X2,XK)

CR(X3,X4)

.....

CR(X3,XK)

...

.
CR(XK-1,XK)

SYMBOL

DEFINITION

M(XK)

Mean of Kth value

V(XK)

Variance of Kth value

SD(XK)

Standard deviation of Kth value

CV(XK,X1)

Covariance of Kth and Ith value

CR(XK,X1)

Correlation of Kth and Ith value

MAXIMUM NUMBER OF POSSIBLE
OUTPUTS

No limitation exists on the number of inputs that
can be processed by the COV/CORR
Instruction, but the processing time and
Intermediate Storage requirements increase
rapidly. The instruction requires that the input
values reside sequentially in Input Storage.
Since the number of outputs is specified for each
type of statistical calculation, the instruction
starts with the first value, working sequentially
through the input values. For this reason, the
order of the input values determines which
values are processed.

Table 10-2 shows the maximum number of
outputs which can be generated and the output
order for K input values located sequentially in
Input Storage. The output order shown in Table
10-2 flows from left to right and top to bottom.

INSTRUCTION PROCESSING
The CV/CR Instruction contains 3 separate
processing phases:

Input Processing

Averaging Period Processing

Output Processing

The Input Processing phase is where new input
values are received, the necessary squares or
cross products formed, and the appropriate
summations calculated as required by the
desired final output. The rate at which the
measurements can be made, the input values
ordered, and the input processing phase
completed without interruption determines the
maximum rate of execution (see Execution
Time).