1. LabVIEW: Tips & Tricks
Ihor Korolov
March 2011

2. Contents GPIB communication
VISA: GPIB and Serial port configuration and communication
How to create and use *.dll in LabVIEW (C++ example)
LabVIEW Tips and tricks:
VI hierarchy
Event structure
Application control (property node and invoke node)
How to execute system command
…..
Creating an executable VIs
Remote panel connection manager and Web publishing tool
I. Korolov: LabVIEW: Tips & Tricks

3. GPIB
I. Korolov: Tips & Tricks

4. GPIB General Purpose Interface Bus (GPIB)
(IEEE-488 is a short-range digital communications bus specification)
8 data lines, 3 Handshaking lines, 5 Interface management lines
HS488 can transfer up to 8 Mbytes/s (2 m cable)
All GPIB devices and interfaces must have a unique GPIB address between 0 and 30.
Address 0 is normally assigned to the GPIB interface. The instruments on the GPIB can use addresses 1 through 30. GPIB devices can be talkers, listeners, or controllers.
I. Korolov: LabVIEW: Tips & Tricks

5. GPIB General Purpose Interface Bus (GPIB) GPIB-USB GPIB-RS232 GPIB-PCI
(IEEE-488 is a short-range digital communications bus specification)
8 data lines, 3 Handshaking lines, 5 Interface management lines
HS488 can transfer up to 8 Mbytes/s (2 m cable)
GPIB-USB
GPIB-RS232
GPIB-PCI
I. Korolov: LabVIEW: Tips & Tricks

6. GPIB - LabVIEW
Use the GPIB functions to exchange data and instructions between VIs and GPIB 488 devices
You should consider initializing the bus with the "GPIB Initialization" function before starting R/W
I. Korolov: LabVIEW: Tips & Tricks

7. Virtual Instrument Software Architecture
I. Korolov: Tips & Tricks

8. Virtual Instrument Software Architecture (VISA)
NI-VISA
Virtual Instrument Software Architecture (VISA)
is a standard for configuring, programming, and troubleshooting instrumentation systems comprising GPIB, VXI, PXI, Serial, Ethernet, and/or USB interfaces.
The majority of modern instrument drivers are based on theVISA
NI-VISA is the National Instruments implementation of the VISA I/O standard
Software libraries
Interactive utilities
(NISpy, VISA interactive control)
Configuration programs
(MAX)
The creation of a new VISA driver in LabVIEW is relatively straightforward and quick process
LabVIEW Application
LabVIEW VI Library
VISA
Operating System
Hardware Link
(GPIB, Serial, VXI …)
Instrument
I. Korolov: LabVIEW: Tips & Tricks

9. Write command from the Write Buffer control to the device
GPIB - VISA
Simple GPIB-VISA session
Open
Write
command/data
Read
data
Close
Open a VISA Session to the instrument resource. Also set the timeout.
Write command from the Write Buffer control to the device
Read the data returned from the NI
Close the VISA Session.
If possible, try to use the VISA functions instead of GPIB because of VISAs versatility
I. Korolov: LabVIEW: Tips & Tricks
GPIB- VISA

10. Using serial ports
Serial communication uses a transmitter to send data, one bit at a time, over a single communication line to a receiver
Serial (RS-232) port
4 x RS-232 to PCI
RS-232 to USB
No Flow Control PC
Device 2 2 3 3 5 5
Cable connection over RS-232 interface
For hardware flow control (RTS/CTS)
Connector pins definition
I. Korolov: LabVIEW: Tips & Tricks

11. Serial- VISA and driver
VISA serial
Simple Serial-VISA session (similar to GPIB-VISA)
Configure
Serial port
Write
command/data
Read
data
Close
Write bytes to port.
Read the number of bytes specified
Close session to port
Configure Serial port (baud rate, data bits, parity, stop bits and flow control)
Closing the serial port allows it to be used by other applications without quitting LabVIEW.
Note: To read an information from a serial instrument, first run the “Bytes at Port” vi. This VI checks how many bytes of information are waiting at the serial port. Use this VI in a while loop to wait for a specified number of bytes accumulated in the buffer before you read the information.
I. Korolov: LabVIEW: Tips & Tricks
Serial- VISA and driver

12. How to create and use DLL
I. Korolov: Tips & Tricks

13. What is DLL? Dynamic-Link Library
DLL is a file which does a particular job, and allows other programs to use its efforts in assisting the program's job. Some programs use a DLL so that they won't need to spend time figuring out how to do that job*
Applications and DLLs can link to other DLLs
How to create *.dll (C++ example)
Borland C++ Compiler
(Free)
(Free)
Code::Blocks (New project)
Our function
This function is called
when DLL is loaded or
unloaded
The WinAPI, is Microsoft core set of application programming interfaces (APIs) available in Microsoft Windows op. systems *
I. Korolov: LabVIEW: Tips & Tricks

14. How to create DLL? The syntax of a function declaration Func1 = a + b
In Borland C/C++
DWORD WINAPI Function (DWORD a, DWORD b, …..);
Long WINAPI Function (float *a, long b, float *c, ….);
In Microsoft C++
_declspec (dllexport) DWORD Function (DWORD a, DWORD b, …..);
_declspec (dllexport) long WIAPI Function (float *a, long b, float *c, ….);
Func1 = a + b
a0 = a*a*a
b0 = b*b
avg = (a[0] + a[1] +…+ a[size-1]) / size
I. Korolov: LabVIEW: Tips & Tricks
Code blocs

15. How to create DLL? Our dll The header file *.h Build dll
All of the functions we have created in the source code are available to other applications
Build dll
I. Korolov: LabVIEW: Tips & Tricks
Code blocs

16. How to use DLL in LabVIEW?
???
The DLL can be called by using the LabVIEW Call Library Function
1. Path (dll location)
2. Function name
I. Korolov: LabVIEW: Tips & Tricks

17. How to use DLL in LabVIEW?
???
Data types LabVIEW/C++
unsigned char BYTE; // 8-bit
unsigned short WORD; // 16-bit
unsigned long DWORD; // 32-bit
………………. ………………….* *
Instrument
1.dll
2.dll
I. Korolov: LabVIEW: Tips & Tricks
ExampleDLLs

18. Tips & Tricks
I. Korolov: Tips & Tricks

19. VI hierarchy View VI Hierarchy
The “VI Hierarchy” window displays a graphical representation of all open LabVIEW projects and targets, as well as the calling hierarchy for all VIs in memory, which includes type definitions, global variables, LabVIEW classes and dynamic member VIs, etc. Use this window to view the subVIs and other nodes that make up the VIs in memory and to search the VI hierarchy*.
   
Redo Layout—Repositions the hierarchy nodes after you expand, collapse, or move nodes.
Vertical Layout—Arranges the nodes from top to bottom, placing roots at the top of the layout.
Horizontal Layout—Arranges the nodes from left to right, placing roots on the left side of the layout.
Include VI Lib—Includes VIs in labview\vi.lib in the hierarchy layout.
Include Globals—Toggles the hierarchy layout to include or exclude global variables.
Include Type Definitions—Toggles the hierarchy layout to include or exclude type definitions. *
I. Korolov: LabVIEW: Tips & Tricks
Example LP MD

20. Event structure
The Event structure waits until an event happen, then executes appropriate case to handle that event
Place the event structure on the block diagram
Right click on the structure border Add event case
Configure which events to handle
I. Korolov: LabVIEW: Tips & Tricks
Example Event

21. Ctrl + Scroll Through Structure
Use Ctrl + Mouse Scroll to scroll through:
Case Structures
Event Structures
Stacked Sequence Structures
Diagram Disable Structures
Ctrl +
I. Korolov: LabVIEW: Tips & Tricks
Example Scroll

22. Property node and Invoke node
Property nodes is used to get and set VI, object, or application properties
Right click
Invoke nodes is used to perform actions, or methods on VI object, or application
Property node
The “OK” button will start blinking
if the “Blinking” button is pressed
I. Korolov: LabVIEW: Tips & Tricks
Example PN

23. Property node: Cursors
assist in viewing data points
can be assigned to different plots
lock to plot to help reading data
I. Korolov: LabVIEW: Tips & Tricks
Example PN

24. Open VI Reference This method requires a path to *.vi
I. Korolov: LabVIEW: Tips & Tricks
Example PN

25. This code will run a windows calculator
Sound, Dialog and User interface
Sound
Dialog and
User interface
Run a system command
This code will run a windows calculator
I. Korolov: LabVIEW: Tips & Tricks
Examples

26. Creating an Executable
I. Korolov: Tips & Tricks

27. Creating an executable
With the Application Builder, you can create an executable from any operational LabVIEW VI that will run as a standalone program on any other machine with the same operating system.
Save Vi
New project (add)
Build specification ->Right click
New -> Application (exe)
I. Korolov: LabVIEW: Tips & Tricks

28. Creating an executable
Build specification ->Right click
New -> Application (exe) 2 3 1 4
I. Korolov: LabVIEW: Tips & Tricks

29. Creating an executable
After you have pressed the "Build" button and Application Builder finishes writing the executable to disk, you are ready to run it.
Regardless of your Application Builder and LabVIEW version, you must always install any required driver files on the target machine (e.g. NI-DAQ, NI-488.2)
Install LabVIEW Runtime engine on your target computer (~100 MB). The runtime engine allows you to run LabVIEW executables without needing further LabVIEW on your or target PC.
Run your application.exe on the target computer
Build specification ->Right click
New -> Installer
You can also create an installer:
I. Korolov: LabVIEW: Tips & Tricks
example

30. Remote panel
Web publishing tool
I. Korolov: Tips & Tricks

31. Remote panel and VI/Web server
Remote Panels allow multiple clients to simultaneously view/control the front panel of the same VI
Client machine
Controlling remote panel
LAN
WAN
Server machine
Main panel and Application
Client machine
Viewing remote panel
I. Korolov: LabVIEW: Tips & Tricks

32. Remote panel connection manager
Enable the LabVIEW VI/Web Server on the server machine
Connect and execute remote panels on the client machine
Two main steps to connect: 1
Allow access 2
Tools Options
Operate Connect to remote panel…
I. Korolov: LabVIEW: Tips & Tricks
example

33. Web publishing tool Tools
Web server
The “web publishing tool” is used to view the front panels of VIs on the Web.
! Do not forge to enable the LabVIEW Web Server on the server machine
Web publishing tool Tools
Web browser
To display front panels on the Web, the VIs must be in memory on the computer
Local PC
I. Korolov: LabVIEW: Tips & Tricks
Example MD

34. Tips and Tricks on the LabVIEW Wiki
Useful links
National instruments
Tips and Tricks on the LabVIEW Wiki
Learn LabVIEW
Books
NI forum
I. Korolov: LabVIEW: Tips & Tricks

35. Köszönöm for your attention!
I. Korolov: LabVIEW: Tips & Tricks