System Functions

You can access system functions when you create or edit a function under Configuration ‣ General ‣ Functions and on the Elements tab, you expand FUNCTIONS –> SYSTEM.

System functions are predefined by NEXUS and cannot be edited, however, you can use them as they are or when you build your own functions. System function elements in the NEXUS IC database can be broken up into character/string functions, mathematical functions and other functions. See below for more details about some of the main functions:

Character/String Functions

Function	Description	Example of Use
ASCII	Returns the ASCII code value of the leftmost character of a character expression.	ASCII(‘Alphabet’) = 65
Chr	Converts an ASCII code to a character.	CHR(65) = ‘A’
InStr	Returns the starting position of the specified expression in a character string.	INSTR(‘CORPORATE FLOOR’,’OR’, 3) = 14 INSTR(‘CORPORATE FLOOR’,’OR’, 1) = 2
Len	Returns the number of characters of the given string expression.	LEN(‘Alphabet’) = 8
Length	Same as LEN.	LENGTH(‘Alphabet’) = 8
Lower	Returns a character expression after converting uppercase character data to lowercase.	LOWER(‘Alphabet’) = ‘alphabet’
LTrim	Returns a character expression after removing leading blanks.	LTRIM(’ Alphabet’) = ‘Alphabet
Replace	Replaces all occurrences of the 2nd given string in the 1st string with a 3rd string.	REPLACE(‘Alphabet’,’ph’,’f’) = ‘Alfabet’
RTrim	Returns a character string after truncating all trailing blanks.	RTRIM(‘Alphabet ‘) = ‘Alphabet’
SubStr	Returns a part of a character expression.	SUBSTRING (‘Alphabet’,0,6) = ‘Alpha’
Upper	Returns a character expression with lowercase character data converted to uppercase.	UPPER(‘Alphabet’) = ‘ALPHABET’

Mathematical Functions

Function	Description	Example of Use
Abs	Returns the absolute, positive value of the given numeric expression.	ABS(-15) = 15
ACos	Returns the angle, in radians, whose cosine is the given value.	ACOS(.3) = 1.26610367
ASin	Returns the angle, in radians, whose sine is the given value.	ASIN(.3) = .304692654
ATan	Returns the angle in radians whose tangent is the given value.	ATAN(.3) = .291456794
Ceiling	Returns the smallest integer greater than, or equal to, the given numeric expression.	CEILING(15.7) = 16
Cos	Returns the trigonometric cosine of the given angle (in radians).	COS(180 * 3.14159265359/180) = -1
Erf	Gaussian Error function. See https://en.wikipedia.org/wiki/Error_function	ERF(0) = 0
Exp (10^x)	Returns the exponential value of the given numeric expression.	EXP(4) = 54.59815
Exp (e^x)	Returns the exponential value of the given numeric expression.	EXP(4) = 54.59815
Floor	Returns the largest integer less than or equal to the given numeric expression.	FLOOR(15.7) = 15
InvErf	Inverse Gaussian Error Function	INVERF (0.25) = 0.225312071859631
IsNumber	Returns true if the Alphanumeric input can be converted to a Whole Number.	ISNUMBER(“three”) = false
IsNumeric	Returns true if the Alphanumeric input can be converted to a Numeric.	ISNUMERIC(“three point one four”) = false
Ln(x)	Returns the natural logarithm of the given numeric expression.	LN(95) = 4.55387689
Log(x)	Returns the base-10 logarithm of the given numeric expression.	LOG(100) = 2
Log_b(x)	Returns the base-b logarithm of the given numeric expression.	LOG_B(2, 256) = 8
Round	Returns a numeric expression, rounded to the nearest whole number.	ROUND(15.193) = 15
RoundTo	Returns a numeric expression, rounded to the specified length or precision.	ROUNDTO(15.193,1) = 15.2 ROUNDTO(15.193,-1) = 20
Sign	Returns the positive (+1), zero (0), or negative (-1) sign of the given expression.	SIGN(- 15) = - 1
Sin	Returns the trigonometric sine of the given angle (in radians).	SIN(30 * 3.14159265359/180) = .5
SqRt	Returns the square of the given expression.	SQRT(26) = 5.09901951
Tan	Returns the tangent of the input expression.	TAN(135 * 3.14159265359/180) = -1
ToNumeric	Converts the input to a numeric data type. (Use Concatenate to go the other way.)	TONUMERIC(‘123’) = 123 TONUMERIC(TODATE(‘22 April 2005’)) = 38462
Trunc	Returns n truncated to a whole number.	TRUNC(15.79) = 15.7
TruncTo	Returns n truncated to m decimal places. m can be negative.	TRUNCTO(15.79,1) = 15.7 TRUNCTO(15.79,-1) = 10
UnitExample	Used under the hood to provide examples in Configuration ‣ General ‣ Configure Unit Types	n/a

Compare Functions

There are a variety of Compare functions (“Compare A = B”, “Compare A < B”, “Compare (A = B and C = D) or (E in (F, G, H) and I = J)”, etc.) They all compare the various inputs in the way described in the function name.

Date/Time Functions

Function	Description	Example of Use
CurrentDate	Returns the current system date.	CURRENTDATE( ) = <Today’s current date>
CurrentDateTime	Returns the current system date and time.	CURRENTDATE( ) = <Today’s current date and time>
DateDiff (Day Of Month)	Returns the difference between the day-of-month of two dates. Returns a whole number from -30 to +30.	DATEDIFF (DAY OF MONTH)(2005-04-22, 2006-06-12) = 10
DateDiff (Days)	Returns the number of days between two dates.	DATEDIFF (DAYS)(2005-04-22, 2006-06-12) = -416
DateDiff (Month of Year)	Returns the difference between the month-of-year of two dates. Returns a whole number from -11 to +11.	DATEDIFF (MONTH OF YEAR)(2005-04-22, 2006-06-12) = -2
DateDiff (Months)	Returns the number of months between two dates.	DATEDIFF (MONTHS)(2005-04-22, 2006-06-12) = -13.667
DateDiff (Years)	Returns the number of years between two dates.	DATEDIFF (YEARS)(2005-04-22, 2006-06-12) = -1.139
Day	Returns the Day part of a date.	DAY(2005-04-22) = 22
LastInspectionDate	Returns the last inspection date for a component.	N/A
Month	Returns the Month part of a date.	MONTH(2005-04-22) = 4
NextInspectionDate	Returns the next inspection date for a component.	N/A
ToDate	Converts the input value to date data type.	TODATE(38462) = 2005-04-22 TODATE(‘22 April 2005’) = 2005-04-22
Year	Returns the Year part of a date.	YEAR(2005-04-22) = 2005

Special System Functions

Function	Description	Example of Use
System - Anomaly - Risk Score	Used to set up the anomaly risk matrix. Calculates the actual risk score of each anomaly. The result of this function is a number that will be used to position the anomaly in the corresponding square inside the risk matrix.	See Set Up Anomaly Risk Matrix.
System - Audit Log Change Item	Extracts and provides the name of a row from Sync_Change.	SYSTEM - AUDIT LOG CHANGE ITEM (3806961) = (2024-Wellsite A) Coating Assessment on Wood / Offshore / 24” PL
System - Audit Log Change Summary	Extracts and provides a summary of all change fields from the Sync_Change row.	SYSTEM - AUDIT LOG CHANGE SUMMARY (3806961) = Event: “” -> “Coating Assessment #48”, Is Completed: “No” -> “Yes”

Other Functions

Function	Description	Example of Use
IsNull	ISNULL(A, B) returns A if A is not null; or B if A is null. The syntax for this function is ISNULL(check_expression, replacement_value), where check_expression is the expression to be checked, and replacement_value is the expression to be returned if check_expression is NULL. check_expression can be of any type. replacement_value must have the same type as check_expression. Note that an alphanumeric field that contains an empty string is not null — to set the field value back to null, click the “X” button at the right of the field.	ISNULL(<null>, 10) = 10 ISNULL(30,10) = 30
Linear Interpolation	Specify Ymin, Ymax, Xmin and Xmax, and for a given Xset, this function will return Yset. Note: Xmin, Xmax, and Xset cannot have date data type as their input. If you need to interpolate between dates, then first convert the date inputs to a numeric data type.	LINEAR INTERPOLATION(0,0, 2,4, 1) = 2
Length	Calculates length from two parameters, i.e. ABS(Param2 - Param1)	LENGTH(5.418 – 6.254) = 0.836
PassThru	Returns parameter value without modifying its display type.	PASSTHRU(‘Alphabet’) = ‘Alphabet’ PASSTHRU(123) = 123