Object Tree

While editing your script, the object tree helps you by providing the object names. You can extend the branch of the object tree by placing a + icon in from of the name or by double-clicking the branch name. A double-click on one of the entries inserts the corresponding text in the EbsScript edit field

• at the cursor position, or
• as replacement of the script text selected earlier.

As such, writing or syntax errors can be avoided in the definition of the names.

The object tree is built every time the EbsScript Editor is started. If you delete, insert or rename components or pipes in the model, you must rebuild the object tree by using the command "Extras"à"Rebuild Object Tree".

The object tree consists of

• a @model branch, which shows the name and the type of all the user-defined variables, which are defined global for all profiles. This branch is absent, if there are no global variables in the model. If you double-click such an item, the correct expression for the assignment of the global variables is inserted e.g. @model.global1. To assign an element from an array, you must insert the index in [ ] e.g. @model.GlobalArray[3].
• a @prof branch, which shows the name and the type of all the profile-dependent user-defined variables.
• a @generaloptions branch, which shows General Options, which you can modify within EbsScript.
• a @calcoptions branch, which permits you to modify the calculation settings for simulation or for validation for the active profile and query information about the last calculation done.
• a @parentoptions branch, which permits you to modify the calculation settings for simulation or validation for the current parent profile and query information about the last calculation done for this profile
• a branch for each component and each pipe in the model (see Components / Pipe Entries). These branches are arranged alphabetically.

To close a branch again, click on the - icon before the name.

Sometimes, there are sub-branches under the main branch. These sub-branches can be expanded and closed in the same way.

At the top of the tree display there is a text field that can be used to filter the tree display. There is also a drop-down button to the right that displays filter options.

As long as no capital letters are entered, the search is not case-sensitive. As soon as at least one capital letter is entered, the search is case-sensitive. If the search text begins with inverted commas ("), then the text must begin with the search text; if the search text ends with inverted commas, then the text must end with the search text.

In the object tree, the dot (.) is also used to search in the individual levels of the tree. A search text for the next level is created with each point. A search text can thus be created for each level (which can also contain inverted commas, for example).

The "Ignore namespaces" option ignores macro namespaces during the search, i.e. all objects (including those in macros) are searched for in the top level.

Components / Pipe Entries

When you open the branch for a component or a pipe in the object tree, you see the attributes of these objects.

 

For a component, these are

• the specification values (including the reference values for the off-design calculations, which appear in blue in the component property sheet)
• the result values
• the characteristic lines

When you expand an entry for a characteristic line, you can see the sub-entries getSize, param (if available), x and y. Double-click on getSize or on param to copy the expressions in the edit field, which are necessary for accessing the number points or the parameters of the characteristic lines. A parameter is available only when the corresponding characteristic line of the component possesses a parameter. By means of an double-click on x or y, copy the expressions in the edit field, which permit the access to a specific point (x or y value) of the characteristic line. You must specify the index in brackets [ ] e.g. Gas_turbine.CT2_1.y[2]. Note that the indices start with 1.

 

For a pipe, these are

• the calculated thermodynamic properties of the pipe such as pressure, temperature, entropy, etc.
• the calculated material composition of the fluid in the pipe.

Note that EbsScript offers read and write access to all values. Still, it is not advisable to modify the result values, because these are overwritten in the next calculation. More information about the units of the values is given in EbsScript Introduction.

In the specification property sheet of the components, there are certain entries, for which no value is to be entered, but instead an entry is to be selected from a drop-down list. The values are known as flags (their names start with an F). To access these flags from EbsScript, you must use the numeric values, which match the entries in the drop-down list. The numbers are given in the online Help or in the Excel templates. In the Standard Excel templates, you can move the mouse pointer over the red triangle in the corresponding Excel cell, which displays a tool-tip window showing the values of the numbers. Alternatively, you can also attach a value cross to the component and let the numeric value be displayed by disabling the check box "Value as Text".

A difficulty arises when you use object names that start with a number (e.g. a measurement point with the name 1RM00T011) . This would not be a problem for EBSILON^®Professional, but in the naming conventions of PASCAL, the names must start with an alphabet. For this reason, the compiler gives an error message. To avoid this, the name must be placed in brackets. [ ]. Example: to access the measured value of the given measurement point, one uses the expression

[1RM00T011].MEASM

Options

 

Model Settings

When you expand the branch @calcoptions or @parentoptions, you can see a list of expressions, which can be used in EbsScript for setting the options that are used for calculations. These expressions correspond to the options, which can be accessed through the tabs Simulation, Validation, Results and User-defined Fluids in the window "Extras"à"Model Options".

With EbsScript, you can use and set each of these options.

	Option in the Model Options Window	EbsScript expression	Valid values in EbsScript
Simulation	Maximum number of iterations	itmax	> 17
	Global calculation mode	globalmode	0 for Design 1 for Off Design
	Start of component relaxation (ITRX)	startrelax	> 17
	Component relaxation till ITRX	relaxupto	0 for 0 1 for 1 till 7 for 7
	Component relaxation after ITRX	relaxafter	0 for 0 1 for 1 till 7 for 7
	End of the iteration at an accuracy of	matprec	0 for 10-4 1 for 10-5 2 for 10-6 3 for 10-7
	Version of the Stodola law used for turbines in off-design	stodola	0 for the old version (ideal gas) 1 for the new version (real gas)
	Extreme relaxation	extrelax	0 for No 1 for Yes
	Water-steam table	watersteamtable	0 for IFC-67 1 for IAPWS-IF97
	Air-/Flue gas table	gastable	0 for FDBR 1 for VDI 2 for real gases
	Reference temperature for net calorific value	ncvreftemp	Temperature in °C
	Parameter Alpha_T for radiation temperature	alphat	0 <= alphat <= 1
	Flag, whether calculation time restriction is to be active	usemaxtime	0 for No 1 for Yes
	Maximum calculation time	maxtime	Calculation time in seconds
Validation	End of the iteration at an accuracy of	val.matprec	0 for 10-3 1 for 10-4 2 for 10-5
	Relaxation validation	val.relax	0 for 0 1 for 1 till 5 for 5
	Validation method	val.method	0 for Ebsilon Standard 1 for VDI 2048 2 for Lagrange
	Consideration of the material uncertainties	val.table_uncertainties	0 for No 1 for Yes
Results	Type of the last calculation	res.type	1 for Simulation, 2 for Validation
	Status of the calculation (see Chapter: Getting Started -->Model Options -->Results --> General)	res.status (outdated)	0: Successful  0: Successful with Comments 1: Successful with warnings 2: Maximum number of iterations reached / Comments 3: Maximum number of iterations reached with warnings 4: Calculation error 5: Error before calculation 6: General error 7: Maximum calculation time exceeded
		res.status2 (new)	0: Successful                1. Successful with Comments                2: Successful with Warnings 3: Error in Calculation                4: Error before Calculation /    Calculation not possible                5: General Error                6: Maximum of Iterations reached 7: Maximum of Iterations reached with Warnings                8: Maximal Calculation-Time exceeded 9: Maximum of Iterations reached with Errors                10: License-Error    11. Already in Simulation Error 12. Internal-Error
	Total of the error squares during validation	res.sqval	>=0.0
	Number of degree of freedom in validation	res.freigr	>=0
	Number of iterations	res.iter	>=0
	Calculation time (in ms)	res.time	>=0
	max. residual time (in ms)	res.rtimemax	>=0
	Chi^2-Test ratio during validation	res.chi2	>=0.0
User-defined Fluid	a1 (Coefficient of the cp-polynomial)	usr.a1	real number
	a2 (Coefficient of the cp-polynomial)	usr.a2	real number
	a3 (Coefficient of the cp-polynomial)	usr.a3	real number
	a4 (Coefficient of the cp-polynomial)	usr.a4	real number

 

General Settings

The General Settings, which can be accessed through the EBSILON^®Professional main menu through "Extras"à"General Settings", are mostly irrelevant for the EbsScript execution. There is one exception, where it is useful to modify the entry within the EbsScript: When you do a design calculation, EBSILON^®Professional should know, whether reference values for the off-design calculation are to be updated or not. This is done via the variable @generaloptions.takeovernv:

• If you set this expression to 0, you can carry out a design calculation without overwriting any reference value in your model.
• If you set this expression to 1, the reference values are saved in your model, after you have done a design calculation.

 

Option in the window "General Settings", tab"Calculation"	EbsScript expression	Valid values in EbsScript
Takeover nominal values	takeovernv	0 for No 1 for Yes

Other general options cannot be modified by EbsScript. Features, which require user interaction or an automatic output (e.g. for the validation results), are disabled during the EbsScript execution.