Item type: Function item
This Item is a calculated value based on existing items in Hive. The calculation is formula based on inputs from external Items.
The Function item item type has the following properties:
| Name | Description | ID | Flags |
|---|---|---|---|
| Expression | An expression used to calculate the value of this item | 5110 | Persisted |
| External Items | The external items are identified as 'ex1, 'ex2, ..., 'exN' in the formula given by the Expression property. | 20000 ... 20000+N | Persisted |
| Quality | Item quality | 3 | NormalPage |
| Rights | Item access rights | 5 | ReadOnly |
| Time | Item timestamp | 4 | NormalPage |
| Type | Item canonical datatype | 1 | ReadOnly |
| Value | Item value | 2 | NormalPage |
| Valuetype | Item canonical datatype. | 19100 | Persisted, Enumerated |
See also Predefined Item Properties and OPC DA Properties
Calculation
The formula can an expression with the names ex1, ex2,ex3,...exN. The formula can include the following Operators, Functions, and Logic.
In most cases when using expressions of kind All*, e.g. AllGoodCount, you will most likely need to have the module property ExtItem pass-through quality is set to Any quality.
Otherwise, one or more external item having a bad quality will prevent the Function item from being evaluated completely.
See also: ExtItem pass-through quality.
| Operator | Description | Example | Item Type |
|---|---|---|---|
| + | The sum of two values | ex1 + ex2 | 8 byte float (default) |
| - | The subtraction of one value from another | ex1 - ex2 | 8 byte float (default) |
| * | The multiplication of two values | ex1 * ex2 | 8 byte float (default) |
| / | The division of one value by another | ex1 / ex2 | 8 byte float (default) |
| % | The modulus of one value by another | ex1 % ex2 | 8 byte float (default) |
| Function | Description | Example | Item Type |
|---|---|---|---|
| ( | Left bracket | 1.0 / ( ex1 + ex2 ) |
|
| ) | Right bracket | 1.0 / ( ex1 + ex2 ) |
|
| /**/ | Comment. In a function Item everything between /* and */ will be omitted. | /* a comment */ | |
| abs | The absolute value | abs(ex1) | 8 byte float (default) or custom scalar number |
| asinh | Represents the inverse of the hyperbolic sine function | asinh(ex1) | 8 byte float (default) or custom scalar number |
| acosh | Represents the inverse of the hyperbolic cosine function. | acosh(ex1) | 8 byte float (default) or custom scalar number |
| atanh | Represents the inverse of the hyperbolic tangent function. | atanh(ex1) | 8 byte float (default) or custom scalar number |
| arcsin |
Returns the angle, θ, measured in radians, such that -π/2 ≤θ≤π/2 . The argument is a number must be greater than or equal to -1, but less than or equal to 1
Remarks: A positive return value represents a counterclockwise angle from the x-axis; a negative return value represents a clockwise angle. Multiply the return value by 180/Math.PI to convert from radians to degrees |
arcsin(ex1) | 8 byte float (default) or custom scalar number |
| arccos |
Returns the angle, θ, measured in radians, such that 0 ≤θ≤π. The argument is a number must be greater than or equal to -1, but less than or equal to 1
Remarks: Multiply the return value by 180/Math.PI to convert from radians to degrees. |
arccos(ex1) | 8 byte float (default) or custom scalar number |
| arctan |
Returns the angle, θ, measured in radians, such that -π/2 ≤θ≤π/2. -or- NaN if d equals NaN, -π/2 rounded to double precision (-1.5707963267949) if d equals NegativeInfinity, or π/2 rounded to double precision (1.5707963267949) if d equals PositiveInfinity.
Remarks: A positive return value represents a counterclockwise angle from the x-axis; a negative return value represents a clockwise angle. Multiply the return value by 180/Math.PI to convert from radians to degrees |
arctan(ex1) | 8 byte float (default) or custom scalar number |
| cos | The cosine of a value, in radians | cos(ex1) | 8 byte float (default) or custom scalar number |
| cosh |
The hyperbolic cosine of value. If value is equal to NegativeInfinity or PositiveInfinity, PositiveInfinity is returned. If value is equal to NaN, NaN is returned. The parameter is an angle, measured in radians. Remarks: The angle, value, must be in radians. Multiply by Math.PI/180 to convert degrees to radians. |
cosh(ex1) | 8 byte float (default) or custom scalar number |
| exp | Exponent of an expression | exp( ex1 ) | 8 byte float (default) |
| floor | Rounds the value to nearest integer towards minus infinity | floor(ex1) | 16 byte fixed point (default) or custom scalar number |
| ln | Logarithm of a value | ln(ex1 + ex2) | 8 byte float (default) |
| neg | Invert sign | neg(ex1) | 8 byte float (default) or custom scalar number |
| pow | The first value raised to the power of the second value | pow(ex1 , ex2) | 8 byte float (default) or custom scalar number |
| sin | The sine of a value, in radians | sin(ex1) | 8 byte float (default) or custom scalar number |
| sinh |
The hyperbolic sine of value. If value is equal to NegativeInfinity. The parameter is an angle, measured in radians.
Remarks: The angle, value, must be in radians. Multiply by Math.PI/180 to convert degrees to radians. |
sinh(ex1) | 8 byte float (default) or custom scalar number |
| sqrt | The square root of a value | sqrt(ex1) | 8 byte float (default) or custom scalar number |
| tan | The tangent of a value, in radians | tan(ex1) | 8 byte float (default) or custom scalar number |
| tanh |
The hyperbolic tangent of value. If value is equal to NegativeInfinity, this method returns -1. If value is equal to PositiveInfinity, this method returns 1. If value is equal to NaN, this method returns NaN. The parameter is an angle, measured in radians. Remarks: The angle, value, must be in radians. Multiply by Math.PI/180 to convert degrees to radians. |
tanh(ex1) | 8 byte float (default) or custom scalar number |
| max |
Return max value of two values. |
max(ex1,ex2) | 8 byte float (default) or custom scalar number |
| min |
Return min value of two values. |
min(ex1,ex2) | 8 byte float (default) or custom scalar number |
| bit | Return a bit either 0 or 1 | bit(ex1,X) | return the bit X in ex1. X = 0,1,2,3,4,.... |
| allgoodavg |
Return the average of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodavg() | 8 byte float (default) |
| allgoodmin |
Return the minimum of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodmin() | 8 byte float (default) |
| allgoodmax |
Return the maksimum of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodmax() | 8 byte float (default) |
| allgoodmed |
Return the median of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodmed() | 8 byte float (default) |
| allgoodstd |
Return the standard diviation of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodstd() | 8 byte float (default) |
| allgoodvarians |
Return the varians of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodvarians() | 8 byte float (default) |
| allgoodcount |
Return the number of all external items that have good quality. |
allgoodcount() | int |
| allgoodsum |
Return the sum of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodsum() | int (default) |
| allgoodcountvalue |
Return the number of all external items that have good quality and value equal to the given value. |
allgoodcountvalue(5.1) | int |
| allgoodlastdatetime |
Return the newest timestamp of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodlastdatetime() | DATE |
| allgoodlastunixtime |
Return the newest timestamp of all external items that have good quality. The value is a double with ms as decimals. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodlastunixtime() | 8 byte float (default) |
| allgoodfirstdatetime |
Return the oldest timestamp of all external items that have good quality. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodfirstdatetime() | DATE |
| allgoodfirstunixtime |
Return the oldest timestamp of all external items that have good quality. The value is a double with ms as decimals. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodfirstunixtime() | 8 byte float (default) |
| allgoodgreatherthanavg |
Return the the average of all good values greather than X. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodgreatherthanavg(XX) | 8 byte float (default) |
| allgoodlessthanavg |
Return the the average of ajl good values less than X. If no good extenal value exist, then NAN and bad quality is returned. |
allgoodlessthanavg(XX) | 8 byte float (default) |
| allavg |
Return the average of all external items. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allavg() | 8 byte float (default) |
| allmin |
Return the minimum of all external items that have good quality. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allmin() | 8 byte float (default) |
| allmax |
Return the maksimum of all external item. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allmax() | 8 byte float (default) |
| allmed |
Return the median of all external. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allmed() | 8 byte float (default) |
| allstd |
Return the standard diviation of all external items. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allstd() | 8 byte float (default) |
| allvarians |
Return the varians of all external. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allvarians() | 8 byte float (default) |
| allcount |
Return the number of all external items. |
allcount() | int |
| allsum |
Return the sum of all external items. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allsum() | int (default) |
| allcountvalue |
Return the number of all external items that have value equal to the given value. Quality will be the worst quality. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allcountvalue(5.1) | int |
| allgreatherthanavg |
Return the the average of all values greather than X. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
allgreatherthanavg(XX) | 8 byte float (default) |
| alllessthanavg |
Return the the average of all values less than X. If error in conversion to double, the value will be omitted, and quality will be set to BAD |
alllessthanavg(XX) | 8 byte float (default) |
| movingavg |
Calculate the moving average of the last 5 values of calculation defined in the bracketts |
movingavg(ex1) | 8 byte float (default) or custom scalar number |
| movingavgXX |
Create an moving average of last XX values |
movingavg10(ex1) | 8 byte float (default) or custom scalar number |
| deltaavg |
Create an moving average of last 5 values, but the value is only updated when calculation is based on 5 new values. |
deltaavg(ex1) | 8 byte float (default) or custom scalar number |
| deltaavgXX |
Create an moving average of last XX values, but the value is only updated when calculation is based on XX new values. |
deltaavg10(ex1) | 8 byte float (default) or custom scalar number |
| movingtimeavg |
Calculate the moving tima average of the last 5 seconds of calculation defined in the bracketts, Value updates every 5 seconds. First calculated value will be first time a measurement is equal or grearter than next 5 sec expected timepoint. |
movingtimeavg(ex1) | 8 byte float (default) |
| movingtimeavgXX |
Calculate the moving average of the last XX seconds of the calculation defined in the bracketts. If XX is 60, then the function return the moving average of the last 60 seconds. |
movingavg100(ex1) | 8 byte float (default) |
| deltatimeavg |
Calculate the moving time average of the last 5 seconds of the calculation defined in the bracketts. This calculation return a new value ecery 5 second. The calculation is also synchronized in time, a new value at 10:00:00, 10:00:05, 10:00:10, etc. First calculated value will be first time a measurement is equal or grearter than next 5 sec expected timepoint. |
deltaavg100(ex1) | 8 byte float (default) |
| deltatimeavgXX |
Calculate the moving time average of the last XX seconds of the calculation defined in the bracketts. If XX is 60, then the function return the moving average of the last 60 seconds every 60 seconds. The calculation is also synchronized to XX. If XX is 60 a new value will becalculated every minutes e.g. 10:01:00 and 10:02:00 , etc. If XX is 600, there will be a new value at 10:00:00, 10:10:00, 10:20:00, etc. |
deltaavg60(ex1) | 8 byte float (default) |
| delay | Delay the value 1 step. | delay(ex1/ex2) | 8 byte float (default) |
| delayXX | Delay the value XX step. | delay5(ex1/ex2) | 8 byte float (default) |
| pulsedetect | Detect a pulse defined as the previous value below 0.5 and current valiue above 0.5. If a puls is detected the return value is 1 else the value is 0. | pulsedetect(ex1) | 8 byte float (default) |
| pulsecount | Count the number of detected pulses. A puls is defined bu the function pulsdetect. The counting starts from 0 when Apis is started. | pulsecount(ex1) | 8 byte float (default) |
| filetime2oadate |
Converts a FILETIME value into the equivalent OLE Automation date. A Windows file time is a 64-bit value that represents the number of 100-nanosecond intervals that have elapsed since 12:00 midnight, January 1, 1601 A.D. (C.E.) Coordinated Universal Time (UTC). Windows uses a file time to record when an application creates, accesses, or writes to a file. An OLE Automation date is a 8 byte floating-point number whose integral component is the number of days before or after midnight, 30 December 1899, and whose fractional component represents the time on that day divided by 24. The base OLE Automation Date is midnight, 30 December 1899. |
filetime2oadate(ex1) | DATE |
| unixtime2oadate |
Converts a Unix Timestamp into the equivalent OLE Automation date. Unix Timestamp is the number of seconds that have elapsed since UTC 1970-01-01T00:00:00Z. The OLE Automation data type is described above. |
unixtime2oadate(ex1) | DATE |
| unixtimems2oadate |
Converts a Unix Timestamp with milliseconds (Unix time multiplied with 1000), into the equivalent OLE Automation date. Unix Time and OLE Automation data types are described above. |
unixtimems2oadate(ex1) | DATE |
| getdatetime |
Take the timestamp of the value and use this as the value itself. |
getdatetime(ex1) | DATE |
| getunixtime |
Take the timestamp of the value and convert this to Unixtime. The decimal part is milliseconds. |
getunixtime(ex1) | 8 byte float (default) |
| if-elseif-else |
Add possibilities to have IF - ELSEIF - ELSE construction in function Items. ELSE part is mandatory, but the ELSEIF can be omitted or added several times. |
If (ex1 > 2) {ex1*ex2} ElseIf (ex1 > 1) {(ex3+1)*ex1} Else {5.0} |
8 byte float (default) |
| Logic | Description | Example | Item Type |
|---|---|---|---|
| > | Greater than | (ex1 > ex2) | 8 byte float ( 0.0 or 1.0) |
| >= | Greater than or equal | ( ex1 >= 2.5 ) | 8 byte float ( 0.0 or 1.0) |
| < | Smaller than | ( ex1 < 3.4) | 8 byte float ( 0.0 or 1.0) |
| <= | Smaller than or equal | ( ex1 <= ex2 ) | 8 byte float ( 0.0 or 1.0) |
| == | Equal | ( ex1 == ex2 ) | 8 byte float ( 0.0 or 1.0) |
| <> | Not equal | ( ex1 != ex2 ) | 8 byte float ( 0.0 or 1.0) |
| != | Not equal | ( ex1 != ex2 ) | 8 byte float ( 0.0 or 1.0) |
| ! | Not | !( ex1 > ex2 ) | 8 byte float ( 0.0 or 1.0) |
Logical expressions are written like (ex1 > 4.5), the result however will be a double value either 0.0 (false) or 1.0 (true). These expressions can be a part of a formula.
The result of a calculation will always be a double value.
External Items
The values ex1, ex2 are the values from the external items defined in the external items attribute.
Example 1
Expression:
ex1+ex2 + ex1+ 5.14
External Items:
ex1 : Worker.signal1
ex2: Worker.Signal2
Example 2
Expression:
(ex1+3.2) / ex2+5.3 / ( ex2-ex1 )-ex3 + Ln( ex1+ex2 ) * ( ex1 > 5.2 )
External Items:
ex1 : Worker.signal1
ex2: Worker.Signal2
ex3: Worker.Signal4
Example 3
Expression:
Ln( ex1+ex2+ Abs(ex1) )
External Items:
ex1 : Worker.signal1
ex2: Worker.Signal2