Quantity definitions and their units of measure

Physical quantities such as length, temperature, and force can be read into CADMATIC as a plain number or as a combination of a number and its unit of measure. All quantity values are converted in input into floating point numbers that express the value in the base units of the program, which allows the input values to be used in computations regardless of their original unit of measure. The conversion of input values is managed in the quantity definitions configuration object.

• Quantity definitions and their units of measure
• Quantity definition configuration
• Quantity type data fields
• Quantity type ID numbers
• Quantity value output formats
• Example configuration

Quantity definition configuration

In the Project Environment dialog, in [library] > Configuration > Common > Quantity definitions and their units of measure, administrator can define how to convert quantity values in input into the base units of the program. The base unit for length values is millimeters, and the base unit for angle values is degrees.

Opening the configuration object displays the currently defined quantity types.

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A quantity type definition can contain the following data fields:

ID Name OutputFormat Epsilon [NumberOfUnits Unit1 Value1 … Unit5 Value5]

The data fields can be delimited with spaces or tab characters, but you must use an external text editor to be able to insert tabs. You can also add line breaks to improve the readability of the configuration object.

Here is an example definition with two units of measure that allow Nominal Size to be input as millimeters or inches:

0 NS 00%g 0.5 2 mm 1 " 25.4

If the input data does not specify the unit of measure, the program uses the default unit (Unit1) of the quantity type. Each quantity type must be compatible with the base unit: since lengths are stored as millimeters, the default unit of Area must be square millimeters.

Also arithmetic expressions are allowed in input. For example, the following inputs are valid:

• 1m 30mm
• 1 m 30 mm
• 1030
• 1' 2"
• 1' 2_3/4"
• 1m * 20mm
• 300 mm

There are a number of system-defined quantity types that must be present in the configuration. Closing the quantity type editor checks if all the system-defined quantity types are included in the configuration, and if any of them are missing, you are prompted that they are now added.

Quantity type data fields

Quantity type ID numbers

Each quantity type must have a unique identification number.

The identification number is given as a parameter (r2) in Data requests, and it can be one of the following:

• ID >= 0 specifies that the target data represents a numeric quantity, and the quantity type (0=NS, 1=Wallt …) is defined in the quantity definition configuration object.

• ID = -1 specifies that the target data is not to be converted but is used as a string. Using this ID, the format string field "r3" is ignored.

• ID = -2 specifies that the target data is time in seconds, measured from 1.1.1970. The DATE part is to be converted as specified in the format string field "r3". See also DATE and TIME formats.

• ID = -3 specifies that the target data is time in seconds, measured from 1.1.1970. The TIME part is to be converted as specified in the format string field "r3". See also DATE and TIME formats.

• ID = -4, when used in a data request, instructs the program to replace the code value of the tag with the string that the code is mapped to. This requires that the target tag has a coded value set. Attempting to use this mechanism for a non-coded tag results in the tag value being shown as is.

Identification values 0–12 and 30– are reserved for system-defined quantity types.

Identification values 13–29 are available for user organizations to create their own quantity types.

The system-defined quantity types are:

Quantity value output formats

Quantity values are output using the format string "C U cform", which consists of the following elements, written without any spaces:

For more information, see Customized printf formats.

The output unit of the value is selected with U, counting from 0. For example, the default unit for Area is m2, also in P&ID database tables.

The table below shows some examples of format strings and the resulting output for an internal length value of 334.1688 mm. Quantities are assumed to be defined according to the quantity definitions in the CADMATIC example project.

Note: The accuracy of floating point numbers in computers is normally about seven digits. This means that for large numbers the decimals may not be accurate even though they are output.

Example configuration

Example quantity configuration in table format:

* Epsilon value of "Ratio" is always ignored. See Epsilon.