SCS Sensor Configuration Editor

Predefined / Canned Calculated Expressions

When creating a new calculated item SCS allows you to choose from a predefined set of canned functions or create your own custom expression.  This choice cannot be changed once created.   However, if you choose to create a pre-programmed function you can change the function used (see below) by the message at any time.

There are 22 types of predefined functions:

Average (Over Time Span)	Computes the numeric average of a time series for a given time span.
Average (Over Sample)	Computes the numeric average of a time series for a given number of samples.
Polar Average (Over Time Span)	Computes the polar average of a time series, provided in units of degrees, for a given time span. Result is in units of degrees.
Polar Average (Over Sample)	Computes the polar average of a time series, provided in units of degrees, for a given number of samples. Result is in units of degrees.
True Wind Speed and Direction	Computes the scalar true wind speed and direction.
Vector Average (Over Time Span)	Computes the vector average of a time series for a given time span.
Vector Average (Over Sample)	Computes the vector average of a time series for a given number of samples.
Standard Deviation (Over Time Span)	Computes the standard deviation of a time series for a given time span.
Standard Deviation (Over Sample)	Computes the standard deviation of a time series for a given number of samples.
Kurtosis (Over Time Span)	Computes the kurtosis of a time series for a given time span.
Kurtosis (Over Sample)	Computes the kurtosis of a time series for a given number of samples.
Skewness (Over Time Span)	Computes the skewness of a time series for a given time span.
Skewness (Over Sample)	Computes the skewness of a time series for a given number of samples.
Pearson Correlation Coefficient (Over Time Span)	Computes the Pearson Correlation Coefficient of a time series for a given time span.
Pearson Correlation Coefficient (Over Sample)	Computes the Pearson Correlation Coefficient for a given number of samples.
Min (Over Time Span)	Computes the minimum numeric value of a time series for a given time span.
Min (Over Sample)	Computes the minimum numeric value of a time series for a given number of samples.
Max (Over Time Span)	Computes the maximum numeric value of a time series for a given time span.
Max (Over Sample)	Computes the maximum numeric value of a time series for a given number of samples.
Sea Level Pressure	Computes the sea level pressure based on a barometer a specified height above sea level.
Heat Index	Computes the heat index based on temperature and relative humidity.
Linear Equation	Computes the scalar value of the linear equation, m * x + b.

 

 

When ACQ outputs a calculated message it formats it similar to a NMEA string.  This means it starts with a sentence label ($DERIV) followed by its comma delimited data with a line feed control character at the end.  

 

The Basic tab consists of the following fields:

• Description
  • Provide an optional description of this item. 
• System Name
  • System generated name, read only format standard across all SCS systems.  
  • Useful for post-processing data on shore from multiple different sources/vessels.
  • Useful for rotating personnel as each ship will always comply with this format.
  • If you wish to have a more user friendly name you can edit the Display Name attribute below
• Display Name
  • User supplied name
  • Can be anything you wish though must be unique.
• Type
  • The Type of Message Definition being defined.  
  • This is set upon creation and cannot be changed after the fact.  
• Log Messages
  • A flag lettings ACQ know if this stream should be logged to disk (files / database) or not.  
  • If unchecked this data will still be available to all clients and calculated devices, but will not be stored on disk.
• Enabled
  • A flag letting SCS know if this interface is actively providing data or if it should be ignored by client applications such as ACQ.
• Sentence Label
  • The value to insert as the first field in the output (read-only)
• Function Selection
  • Allows you to choose which predefined function (see above) you wish to use for this calculation.
• Calculation Parameters
  • Allows you to specify the source data used when executing this calculation.
  • Instead of calculating a result every second like in prior versions of SCS the current version allows you to specify one or more triggers.  When data from a source marked as a trigger is obtained the calculation is executed.  eg if you have a COG from a normal GPS coming in every second and set that as your source then the calculation will be 1x/second but if you have a COG from a POSMV coming in at 10x/second and set that as your source instead then the calculation will occur 10x/second.
• Function Arguments
  • Additional arguments you need (depending on the selected function type) such as the # of samples or length of the time span.

 

The Advanced tab consists of the following fields:

• Comment
  • A general comment pertaining to this item
• Keywords
  • Optional tags used to assist with text searches and metadata
• Log Folder Path
  • If Log Messages is enabled this specified an optional sub-folder for the RAW file containing the message's data
• Delimiters
  • The character(s) to use to split the message into its Data Fields - should be a comma, do not change this!
• Relay via UDP Broadcast
  • A flag which tells ACQ to immediately send the data out via UDP Broadcast the instant it is read from the interface.

 

 

Calculation Parameters and Function Arguments

Each type of function has a set of parameters and arguments which are required to successfully create a valid expression.

Some source data fields are filtered based upon the expected category.  If you are expecting to see something (like your GYRO for a Heading) and it is not in the drop down please double check the source and ensure you have assigned it the correct category.

Calculated data fields can be used in other calculated interfaces allowing for infinite nesting and calculations to be built off of each other.

 

Average (Over Time Span)

Calculation Parameters	A single numeric value you wish to average
Function Arguments	A time span and it's units used to specify the duration of the calculation (eg average every 60 seconds)

 

 

Average (Over Sample)

Calculation Parameters	A single numeric value you wish to average
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset (eg average every 100 values)

 

 

Polar Average (Over Time Span)

Calculation Parameters	A single numeric value (polar/circular) you wish to average
Function Arguments	A time span and it's units used to specify the duration of the calculation (eg average COG every 60 seconds)

 

 

Polar Average (Over Sample)

Calculation Parameters	A single numeric value (polar/circular) you wish to average
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset (eg average COG every 100 values)

 

 

True Wind Speed and Direction

Calculation Parameters	5 source data fields: Speed, Course, Heading, Relative Wind (Speed and Direction)
Function Arguments	- None -

 

 

Vector Average (Over Time Span)

Calculation Parameters	Two numeric values (a scalar/magnitude and a direction) you wish to average
Function Arguments	A time span and it's units used to specify the duration of the calculation (eg average True Wind every 60 seconds)

 

 

Vector Average (Over Sample)

Calculation Parameters	Two numeric values (a scalar/magnitude and a direction) you wish to average
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset (eg average True Wind every 100 values)

 

 

Standard Deviation (Over Time Span)

Calculation Parameters	Two numeric values (a source series and an average) from which you want the standard deviation (σ)
Function Arguments	A time span and it's units used to specify the duration of the calculation

To compute this you may be required to create another Calculated Interface which generates the average which is then used as a parameter in this interface.

 

 

Standard Deviation (Over Sample)

Calculation Parameters	Two numeric values (a source series and an average) from which you want the standard deviation (σ)
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

To compute this you may be required to create another Calculated Interface which generates the average which is then used as a parameter in this interface.

 

 

Kurtosis (Over Time Span)

Calculation Parameters	Three numeric values (a source series, an average and a standard deviation) from which you want the kurtosis
Function Arguments	A time span and it's units used to specify the duration of the calculation

To compute this you may be required to create other Calculated Interfaces which generate the average and standard deviation sources which are then used as parameters in this interface.

 

 

Kurtosis (Over Sample)

Calculation Parameters	Three numeric values (a source series, an average and a standard deviation) from which you want the kurtosis
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

To compute this you may be required to create other Calculated Interfaces which generate the average and standard deviation sources which are then used as parameters in this interface.

 

 

Skewness (Over Time Span)

Calculation Parameters	Three numeric values (a source series, an average and a standard deviation) from which you want the skewness
Function Arguments	A time span and it's units used to specify the duration of the calculation

To compute this you may be required to create other Calculated Interfaces which generate the average and standard deviation sources which are then used as parameters in this interface.

 

 

Skewness (Over Sample)

Calculation Parameters	Three numeric values (a source series, an average and a standard deviation) from which you want the skewness
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

To compute this you may be required to create other Calculated Interfaces which generate the average and standard deviation sources which are then used as parameters in this interface.

 

 

Pearson Correlation Coefficient (Over Time Span)

Calculation Parameters	Four numeric values (two source series and their averages) from which you want the bivariate correlation
Function Arguments	A time span and it's units used to specify the duration of the calculation

To compute this you may be required to create other Calculated Interfaces which generate the averages which are then used as parameters in this interface.

 

 

Pearson Correlation Coefficient (Over Sample)

Calculation Parameters	Four numeric values (two source series and their averages) from which you want the bivariate correlation
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

To compute this you may be required to create other Calculated Interfaces which generate the averages which are then used as parameters in this interface.

 

 

Min (Over Time Span)

Calculation Parameters	One numeric value (two source series and their averages) to compute the minimum value
Function Arguments	A time span and it's units used to specify the duration of the calculation

 

 

Min (Over Sample)

Calculation Parameters	One numeric value (a source series, an average and a standard deviation) ) to compute the minimum value
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

 

 

Max (Over Time Span)

Calculation Parameters	One numeric value (two source series and their averages) to compute the maximum value
Function Arguments	A time span and it's units used to specify the duration of the calculation

 

 

Max (Over Sample)

Calculation Parameters	One numeric value (a source series, an average and a standard deviation) to compute the maximum value
Function Arguments	A numeric value, every time the base sensor value is updated it's sample size is incremented, when that count is equal to this argument the calculation is executed and the counter is reset

 

 

Sea Level Pressure

Calculation Parameters	Two source data fields: Air Pressure, Temperature (in Celsius, Fahrenheit, Rankine, or Kelvin)
Function Arguments	Height of barometer above sea level (in meters).

 

 

Heat Index

Calculation Parameters	Two source data fields: Relative Humidity, Temperature (in Celsius, Fahrenheit, Rankine, or Kelvin)
Function Arguments	- None -

 

 

Linear Equation

Calculation Parameters	One numeric value, the variable x of the linear equation, m * x + b
Function Arguments	Real numbers: Slope m, Offset b

 

 

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