Old Content - visit altium.com/documentation

Parent page: Scripting Languages

This reference describes the VisualBasic Scripting language used to create scripts in Altium Designer. It provides details of the VisualBasic Scripting statements, functions and extensions that are supported in the scripting system.

Also in this reference:

The VBScript language

The Visual Basic Scripting (or VBScript for short) can be used to create scripts that deal with Altium Designer Object Models and Visual Components. In this reference, it's assumed that you are familiar with basic programming concepts and the basic operation of Altium Designer.

The Altium Designer scripting system supports the VBScript language (along with other scripting languages) which is derived from the Microsoft ActiveX Scripting system. So for instance, you should be able to use CScripts or WScripts which are based on the same ActiveX scripting engine that is used in Altium Designer.

All scripting languages supported in Altium Designer are typeless or untyped, which means that a script cannot define records or classes and pass pointers as parameters to functions.

VBScript script example

Sub DisplayName (sName)
  MsgBox "My Name is " & sName
End Sub

Altium Designer and the Delphi RTL

The Scripting system supports a subset of the Embarcadero Delphi Run Time Library (RTL) and the Altium Designer API.

VBScripts scripts can access several Object Models in Altium Designer. For example, the PCB Object Model can be used in VBScripts to deal with PCB objects on a PCB document, or the Workspace Manager Object Model to work with Projects and their documents to extract netlist data.

The Scripting Reference contains information on interfaces with respect to Altium Designer Object Models, components, global routines, types, and variables that make up this scripting language. Consult the Microsoft Visual Basic documentation for more information on VBScript functions.

Server Processes

A script can can be used to execute server processes, which represent commands in Altium Designer.

VBScript Source Files

A VBScript project is organized to store script documents (script units and script forms). A script can be executed from a menu item, toolbar button or from the Run Script dialog from the system menu.

PRJSCR, VBS and DFM files

Scripts are organized into projects with a *.PRJSCR extension. Each VBScript project consists of files with a *.vbs extension. Files can be either script units or script forms — each form has a VBScript script file with *.vbs extension and a corresponding form with a *.dfm extension). A script form is a graphical window (dialog) that hosts different controls that run on top of Altium Designer.

It is possible to attach scripts to different projects, and it's highly recommended to organize scripts into different projects to manage the number of scripts and their procedures / functions. Scripts (script units and script forms) consist of functions/procedures that can be called within Altium Designer.

VBScript examples

The simple examples included in this reference illustrate the basic features of VBScript programming in Altium Designer.

The VBScripts can use script forms, script units, functions and objects from the Altium Designer scripting API, and a subset of functions and objects from the Embarcadero Delphi RTL that are exposed in the scripting system.

Writing VBScript Scripts

This section covers the basic concepts of writing VBScripts in Altium Designer.

VBScript naming conventions

VBScript variables are case insensitive — that is, variables in upper and lower case have the same meaning:


The variables b and B are the same.
b = 60
B = 60

Local and Global Variables

Since all scripts have local and global variables, it is important to have unique variable names in your scripts within a script project. If the variables are defined outside any subroutines and functions, they are global and can be accessed by any unit in the same project.

If variables are defined inside a routine, then these local variables are not accessible outside these routines. Since scripts are typeless, variables are not initialized with their types.

The local variables inside a procedure are automatically initialized.

Variable Initialization

Sub Example
  Dim X
  Dim s
  ' x set to 0
  x =  0
  ' s set to empty
  s = ""
End Sub

Subroutines and Functions

VBScript allows two kinds of procedures; subroutines and functions — a function returns a value only. The syntax of calling a subroutine or function in a script is:

Call SubRoutineA(parameters)
SubRoutine parameters

Subroutine example

Sub SetTheHeight AHeight
  Set Component.Height = AHeight
End Sub

Function example

Function Addone(value)
  AddOne = Value + 1
End Function

Another Function example

Function Test(s)
 Test = S + " rules.."
End Function
Sub DisplayName (sName)
 MsgBox sName
End Sub
Sub Main
Dim S
 S = "Altium Designer"
 DisplayName Test(s)
End Sub

Parameters and Arguments

In VBScript a procedure declaration normally has a list of parameters — note that variables are considered typeless and the scripting system works out automatically what the variable types are. The value used in place of the parameter when you make a procedure call is called an argument.

Example of a subroutine with a parameter

Sub DisplayName (sName)
  MsgBox "My Name is " & sName
End Sub

Example of calling a subroutine

Sub Main
  DisplayName "Altium Designer  Rules"
End Sub

Note that the use of the Call keyword to invoke a subroutine or a function is optional (maintained for backward compatibility).

Comments in scripts

In a script, comments are non-executed lines of code that are included for the benefit of the programmer. Comments can be included virtually anywhere in a script.

With VBScript comments:

  • Any text following ' are ignored.
  • Any text following Rem are ignored.


' This whole line is a comment
REM this whole line is also a comment
DocName = Document.Name ' Get name of active document

Splitting a script line

In VBScript each code statement is terminated on the line (by a CR/LF combination) to indicate the end of the statement. VBScript allows you to write a statement on several lines of code, to split a long instruction over two or more lines, using the underscore character (_).

VBScript does not put any practical limit on the length of a single line of code in a script. However, for the sake of readability and ease of debugging, it is good practice to limit the length of code lines so that they can easily be read on screen or in printed form. If a line of code is very long it can be broken into multiple lines, and this code will be treated by the VB interpreter as if it were written on a single line.

Unformatted code example

If Not (PcbApi_ChooseRectangleByCorners(BoardHandle,"Choose first corner","Choose final corner",x1,y1,x2,y2)) Then EndIf

Formatted code example

If Not (PcbApi_ChooseRectangleByCorners(BoardHandle,_ 
                                        “Choose first corner”,_ 
                                        “Choose final corner”,_ 
                                        x1,y1,x2,y2)) Then EndIf

Using Altium Designer Object Models

The biggest feature of the scripting system is that the Interfaces of Altium Designer objects (Object Interfaces) are available to use in VBScripts. For example, you can update design objects on Schematic and PCB documents through the use of Schematic Interfaces and PCB interfaces respectively.

The Altium Designer Object Interfaces are available for use in any script. Normally in scripts, there is no need to instantiate an interface. The interface representing an existing Altium Designer object is extracted, and from this interface the embedded or aggregate interface objects can be extracted to get or set their property values.

To access a PCB document and its data objects, you first invoke the PCBServer function. By convention, interface names are prefixed by an I character — for example IPCB_Board represents an interface for an existing PCB document in Altium Designer.


' Checks if the current document is a Schematic document
  If SchServer Is Nothing Then Exit Sub
  Set CurrentSheet = SchServer.GetCurrentSchDocument
  If CurrentSheet Is Nothing Then Exit Sub

To have access to a PCB document, invoke the PCBServer.

Creation of a PCB Object Using the PCB Object Model

Sub ViaCreation
  Dim Board
  Dim Via
  Set Board = PCBServer.GetCurrentPCBBoard
  If Board is Nothing Then Exit Sub
  ' Create a Via object
  Via = PCBServer.PCBObjectFactory(eViaObject, eNoDimension, eCreate_Default)
  Via.X = MilsToCoord(7500)
  Via.Y = MilsToCoord(7500)
  Via.Size   = MilsToCoord(50)
  Via.HoleSize   = MilsToCoord(20)
  Via.LowLayer   = eTopLayer
  Via.HighLayer = eBottomLayer
  ' Put this via in the Board object
End Sub

Objects, Interfaces and Functions

Altium Designer Objects, Interfaces and Functions can be accessed in scripts from the following:

  • Client API
  • PCB Server API
  • Schematic Server API
  • Work Space Manager Server API
  • Nexus API
  • Altium Designer API functions
  • Parametric processes.

Reserved Words and Functions

The scripting system supports the VBScript language which is derived from the Microsoft Active Scripting language technology. The reserved words VBScript are:

A, B
Abs, Array, Asc, Atn
Call, Case, CBool, CByte, CCur, CDate, CDbl, Chr, CInt, Class, CLng, Const, Conversions, Cos, CreateObject, CSng, CStr
DateAdd, DateDiff, DatePart, DateSerial, DateValue, Day, Derived Math, Dim, Do, Each, Erase, Escape, Empty, Eval, Execute, Exit, Exp
F,G, H
False, Filter, For, FormatCurrency, FormatDateTime, FormatNumber, FormatPercent, Function GetLocale, GetObject, GetRef, Hex, Hour
I, L, M
If, Is, InputBox, Instr, InStrRev, Int, IsArray, IsDate, IsEmpty, IsNull, IsNumeric, IsObject, Join, LBound, LCase, Left, Len, LoadPicture, Log, LTrim, Maths, Mid, MInute, Month, MonthName, MsgBox
N, O
Next, Nothing, Now, Null, Oct, On Error
Private, Property, Public, Randomize, ReDim, Rem, RTrim, Replace, RGB, Right, Rnd, Round
S, T
ScriptEngine, ScriptEngineBuildVersion, ScriptEngineMajorVersion, ScriptEngineMinorVersion, Second, Select, Set, SetLocale, Sgn, Sin, Space, Split, Sqr, Stop, StrComp, String, StrReverse, Sub, Tan, Then, Time, Timer, Timeserial, TimeValue, Trim, True, TypeName
U, V, W, X, Y
UCase, Unescape, While, Wend, With, VarType, Weekday, WeekdayName, Year

You are reporting an issue with the following selected text and/or image within the active document:
Request Free Trial

Complete this form to request a free 15 day trial of Altium Designer: