Device Checks—11​.10 (h)

"(h) Use of device (e.g., terminal) checks to determine, as appropriate, the validity of the source of data input or operational instruction."

InTouch Numeric Input Validity Check

InTouch can be used to validate source data. The Analog User Input Touch Link can be used to verify that user input is within an allowable range. The figure below shows the Touch Link animation properties window. By entering a Min Value and Max Value user entries of analog data can be forced within a certain range.

Numeric Input Validity Check

AVEVA Industrial Graphics can also be used to validate source data. The User Input Animation can be used to verify that user input is within an allowable range. The figure below shows the User Input Link animation properties window. By checking the Restrict Values check box and entering Minimum and Maximum values user entries of analog data can be forced within a certain range.

Alphanumeric Input Validity Check

The examples above illustrate the validation of user entered analog data. String data can be checked and validated using scripting functions in both InTouch and the IDE. Below is script example that can be executed as an action animation, data change script, or any other method. This example checks a user string entry for length and any illegal special characters. It can easily be modified to perform other validation actions.

Error = 0;

ASCIICode = 0;

IF TestString01 <> "" THEN

FOR Index = 1 TO StringLen(TestString01)

ASCIICode = StringASCII(StringMid(TestString01,Index,1));

IF (ASCIICode >= 48 AND ASCIICode <= 57) OR (ASCIICode >= 65 AND ASCIICode <= 90) OR (ASCIICode >= 97 AND ASCIICode <= 122)

THEN

Error = 0;

ELSE

MessageBox("Entry contained illegal characters. Only alpha-numerics, underscores and dashes are allowed!","Illegal Characters Found",10);

Error = ASCIICode;

EXIT FOR;

ENDIF;

NEXT;

ELSE

Error = 9999;

MessageBox("Entry cannot be null!","Invalid Entry",10); ENDIF;

TestString01 = "";

Data Quality

System Platform maintains a data quality attribute for all tags. Data quality is the degree of validity for a data value. Data quality can range from good, in which case the value is exactly what was originally acquired from the plant floor, to invalid, in which the value is either wrong or cannot be verified. As a data value is acquired, stored, retrieved, and then shown, its quality can degrade along the way, as external variables and events impact the system.

InTouch and the IDE can make use of the IsGood() and IsBad() functions to test the quality of data and make decisions based on the results. See the InTouch HMI online help and the AVEVA Industrial Graphics Editor online help for more information on using the data quality attribute.

Historian can use the data quality attribute in its data logging operations. This allows systems to identify any invalid data that has been logged or captured as part of an electronic record. See the AVEVA Historian online help for more information on how the Historian utilizes data quality information.