Useful LabVIEW 8.20 Features

Useful LabVIEW 8.20 FeaturesUseful LabVIEW 8.20 Features

CS Workshop 2007 February 2nd, 2007

Holger Brand, GSI

January 1st, 2007 [email protected] 2

ContentsContents• Project Explorer• Libraries• Shared Variables• Custom DSC IO Server

– Periodic

– OnChange

• Classes– Simple class hierarchy

• Online Tutorial: How to create and inherit from LVOOP classes

– LVOOP Examples, Graphics.lvproj, Board Testing.lvproj

– LVOOP DesignPatternshttp://wiki.gsi.de/cgi-bin/view/NIUser/LabVIEWObjectOrientedProgramming

• Referenced Object, Singleton, Agent• Factory, Hierarchy Composition, Delegation, Aggregation, Specification,

Channeling, Visitor

• XControls -> Talk of D. Beck

http://wiki.gsi.de/cgi-bin/view/NIUser/LabVIEWObjectOrientedProgramming


Project ExplorerProject Explorer

• A Project contains all project resources–Documents

• *.vi, *.doc, *.html, *.c etc.• organized in Folder and libraries

–Hardware configuration• Local hardware• Remote systems

– Documents

» *.vi, *.doc, *.html, *.c etc.– Hardware configuration

–Dependencies–Build Specifications

•A Project is an Application instance–closed shell or sandbox!–e.g. Queues with the same name are different in different application instances and do not know each other!

- You can supply a project description an define condtional disable symbols


LabVIEW LibrariesLabVIEW Libraries

• A Library defines a namespace– Like package in Java– So, different libraries can contain different VIs with the same name.– A Library-VI name is always automatically prefixed with the library name– A Library-VI is part of the owning Library and can not be opened without.

• It has a version numer, default icon, etc• Library items can have public or private scope

– Private items can be accessed from within the library only

• A library has its own DSC settings


Shared Variables IShared Variables I

• Successor of DataSocket variables• Variable Types

– Single Process• Time stamped, Real-Time-FIFO

– Network published• Buffered, Bind to Source, e.g. OPC item, Single Writer, Real-Time-FIFO

– Time-Triggered• IEEE 1588-Standard, Deterministic Ethernet

• Data Types– All standard data types and array of them, Variant, Bit-Field

– Custom Typedef

• Can be linked to DataSocket, OPC, ChannelAccess, Custom-IO Server• Can have DSC properties: Scaling, Alarming, Trending, Security etc.

• Shared Variable are alway part of a LabVIEW Library


Shared Variables IIShared Variables II

• Tools– Shared Variable

Variable Manager, Multiple Variable Editor, Front Panel Binding Mass Configuration

– DSC-Module• Monitor Variables, View Historical Data

• Migrate: Configuration (.scf), Front Panel Security

• VI Based Server Wizard– On Input Change– Periodic

• Examples– Help->Find Examples...->Browse by Task->Fundamentals->Shared Variable->

Shared Variable Client – Server.lvproj– Help->Find Examples...->Browse by Task->Toolkits and Modules->DataLogging

and Supervisory Control->Fundamentals->DSC Event Structure Demo.lvproj


Custom DSC IO Server ICustom DSC IO Server I

• An I/O server is an application that communicates with and manages input/output devices such as programmable logic controllers (PLCs), remote input/output devices, remote Shared Variable Engines, and data acquisition (DAQ) plug-in devices. These servers read selected input items and write to the selected input items on demand.

• The I/O server starts running when you deploy the project library that defines the server and stops when you stop or undeploy the project library.

• Applications can be used as OPC Server if the Installer includes the Shared Variable Engine

lvconcepts.chm::/Project_Variables.html



lvconcepts.chm::/Project_Libraries.html




Custom DSC IO Server IICustom DSC IO Server II• You might want to create a custom I/O server in the following example

situations: – You do not have an OPC server to handle communication between hardware

and LabVIEW. Custom VI-based I/O servers can interface directly with the hardware and expose data items through the Shared Variable Engine.

– You want to create a simulation server to emulate hardware connections.

• You can create two types of custom I/O servers: – Periodic I/O Server

• does not need controls or indicators on the connector pane• is running continuosly

– On Input Change I/O Server• needs controls and indicators on the connector pane• is called on change of input control value

• MyIOServer.lvproj– MyPeriodicIOServer, MyOnChangeIOServer, MyOnChangeDIMServer


Custom DSC IO Server IIICustom DSC IO Server IIIPeriodic IO Server On Change IO Server


Simple Class HierarchySimple Class Hierarchy

1. Create a new LV-Project: MyFirstClass

2. Create a new class: Automobile1. Add Description

2. Edit Icons

3. Add Attributes: Number of Gears, Number of Doors, Make, Model

4. Add Methods: setAutoAttribute, getAutoAttribute, Start, Stop

3. Create Subclasses1. Truck

1. Add Attributes: Short Bed?, Four Wheel Drive

2. Add Methods: setTruckAttribute, getTruckAttribute

2. Car1. Add Attribute: Number of Seats

2. Add Methods: setCarAttribute, getCarAttribute

4. Create a Main.vi and use that classes