Questions about LabVIEW

Dear support team,
Could someone please respond to Eric's questions? Eric works at Bonneville Power Administration and they are gearing up for another major LabVIEW and DSC project. He may have LabVIEW 7 beta. I am on my way out of town for two weeks and won't have access to phone or email. Thanks!!
Tricia Lee
DSM Inland Northwest
[email protected]
"Pierce, Eric - TNCB-TPP-2"
05/01/2003 08:05 AM
To: [email protected]
cc:
Subject: The list of question i never sent
Sorry for the long delay, things have been very busy here with this new project. I have questions / concerns about the DSC, OPC and LOGOS; first here is our architecture.
We will have two servers running windows 2000 server. Both servers will be live and need to have all DSC components installed. One server is to act as the primary server and the second is to act as a failover server. We have custom components that manage all of our custom services, if one of the custom services stops responding the failover service will shut down all custom services on the primary server and start all of the custom services on the secondary server, thus, the secondary server becomes our primary live server.
My understanding is that we will have to load a *.spf file on each HMI that tells the HMI where the server is, at the same time we need to initialize the DSC and OPC with *spf and *.lpd files. Now I might have the file extensions wrong but the idea is the same. We have all of our data in a SQL 2000 database, how do we make sure that all of the configuration files match the SQL 2000 db? We have several GUI's that can edit the SQL 2000 data, how do we update the DSC / OPC configuration files?
So in short here are my current questions:
How can we manage failover with two live servers
How can we ensure that DSC / OPC / Logos configuration files match the data in SQL 2000?
Does any of this make sense? This labview stuff is very new to me.
Eric Pierce
ACS Group, Inc.
Sr. Software Engineer
w. (360) 619-6284

Hi Eric,
You got it right that once the primary machine goes down, the standby machine detects this, and then loads the appropriate SCF file, etc. Caveat: This would mean however that the hardware in question is accessible by both the machines (it's on an Ethernet, for instance). Any hardware physically connected to the primary machine will obviously be not accessible by the secondary (unless there's a way to have a "Y" connection).
The logging part you mention is not very clear to me. Several questions come to mind: Isn't DSC the logger, logging to its Citadel database? Or, is SQL 2000 the main database? And DSC is logging to SQL 2000? If yes, how? Or is the SQL 2000 querying Citadel and hence getting the data into itself?
Regards,
Khalid

Similar Messages

A question about LabVIEW's instinct.

Hello guys:
I have a question about LabVIEW's nature.
Is LabVIEW a language that can realize the operation system(OS) ?
I feel LabVIEW can express my idea intuitively in my mind.
So LabVIEW can help me develop some program rapidly.
I think LabVIEW can do it.
How about your opinion?

Do you mean can LabView read your mind?
Not by itself, external hardware is required.
Jeff
"´^¤j®ü" wrote in message
news:3b05a593@newsgroups....
> Hello guys:
>
> I have a question about LabVIEW's nature.
> Is LabVIEW a language that can realize the operation system(OS) ?
> I feel LabVIEW can express my idea intuitively in my mind.
> So LabVIEW can help me develop some program rapidly.
>
> I think LabVIEW can do it.
>
> How about your opinion?
>
>
>
>

Question about labview under linux and the using of CIN....

i have a problem with making Code Interface Node (CIN) with labview under LINUX... my goal is to make a CIN that can uses I2C interface (look to libk8000 from hihihihi), but it just work when i'm running it as ROOT ... is there a way to call the cin like as root.... thanks

Hello Mister Pouf,
Can you please explain more your problem? And give more details about it?
Have you receive error message?
Best Regards,
Sanaa TAZI
National Instruments France
Sanaa T.
National Instruments France
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>> http://www.nidays.fr/images/081110_ban_nidays09_468X60.gif

Question about labview block diagram

Hi all,
I'm working on labview with fieldpoint modules. Why can't I connect the FieldPoint IO Point Constant directly to the FP Read (Polymorphic)? It says "I connected 2 terminals of different types". But somehow I found some manuals on NI which said these 2 items could actually be connected. I use Labview 7.1.
Regards,
Nicky
Solved!
Go to Solution.

That Fieldpoint Icon looks different from the one I'm used to seeing. Unfortunately, my PC that has 7.1 on it isn't running anymore, so I can't check that far back.
The error tells you something about what it is looking for (cluster of 2 elements). Turn on context help for the Fieldpoint function. Delete the broken wire and right click on the connector input and select Create Constant. With either of those, you should be able to find out some information as to what is required in that "cluster of 2 elements".
Here is what mine looks like. I am curious to know where you got your Fieldpoint function from. Is it from an older version of LabVIEW than 7.1?
What version of Windows are you using? The font that is showing up on your block diagram looks oddly blocky.
Message Edited by Ravens Fan on 05-10-2010 03:56 PM
Attachments:
Example_VI_BD.png ‏10 KB

Question about LabVIEW generated DLL's

Hello,
I want to try programming games in either JAVA or FLASH.
What I want to know is if I can use the LabVIEW generated DDL's for use in my games, without having to need the LabVIEW runtimes installed.
(in other words, are the LabVIEW generated DLL's, stand alone DLL's as generated in for example C/C++ or other programming languages?)
Second, how good is LabVIEW in converting it's code into a DLL. Can I make complicated algorithms, or are just simple functions allowed.
Hope you guys can spare a few words on this topic.
Sincerely,
Heinen
The Enrichment Center is required to remind you that you will be baked, and then there will be cake.

Hello dan_u and thank you for your quick reply.
If the LabVIEW Runtimes are needed to use the DLL's, that is not a good option for me then. I eventually want to distribute my games over the internet, and having to sent the LabVIEW runtimes with the games is just not an option.
To bad, I'm better in programming stuff in LabVIEW then in writen C++ like code.
Sincerely,
Heinen
The Enrichment Center is required to remind you that you will be baked, and then there will be cake.

Question about LabView 8.0

Installers created from VIs are now compatible with Windows 98, like LabView 6.1?
If not, future version of LabView will be able to create Win98 installers?
With LabView 8.0 can I create smaller installer files?
Thank you in advance.

LV support for windows 98 stopped with version 7.1, so no future version of LabVIEW will support 98, which was replaced over 4 years ago.
The LV run-time engine (which is included with the installer you create) has been getting bigger with every release. When you create the installer, you can choose to remove some of the optional features, which will make the installer size smaller, but not by a great deal. What you can do is instruct users to download the RTE from NI's website and send them only the executable, which will be much smaller than the full installer.
Try to take over the world!

Question about LabVIEW toolkit versions

Hi,
In our systems we have LabVIEW 2012 sp1+ older versions of toolkits such as NI DAQmx (9.7) or NI Flex RIO (13.0 )
I have bought a new system that has all the up to dated toolkit vesrions.For example NI DAQmx (9.9) or NI Flex RIO (13.2). I will install LabVIEW 2012 on this system but I would like to know if I open my VIs in teh system with up to dated drivers then can I open them again in my old systems ( they both use 2012 but driver versions are different) ?
Could you please let me know if I need to re install the old drivers on my new system?
Thanks

tintin_99 wrote:
The problem I have now is I can't install labVIEW 2012 because Runtime engine of 2013 has been insalled on this system. Do I njeed to uninstall 2013 to be able to install 2012?
They should install side-by-side without any issues.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Question about the programming of a legend

Hello everybody,
I have a question about the programming of a waveform's legend. I
already asked here in this forum about the legend programming (03)
months ago.
I went satisfied but I ve just noticed that this code
(See Code old_legend_test.llb with main.vi as main function) operates a
little different from my expectances.
Therefore I have a new question and I want to know if it
is possible by labview programming to plot and show, on a waveform
chart, a signal with activ plot superior to zero (0) without to be
obliged to plot and show a signal with activ plot equal to zero (0) or
inferior to the desired activ plot.
I give you an example
of what I m meaning. I have by example 4 signals (Signal 0, 1, 2 and 3)
and each signal corresponds respectively to a channel (Chan1, Chan2,
Chan3, Chan4). I want to control the legend (activ plot, plot name and
plot color) programmatically. Is it possible with labview to plot signal
1 or 2 or 3 or (1, 3) or (2,3) or (1,2,3) or other possible combination
without to active the signal with the corresponding activ plot zero
(0)?
Let see the labview attached data
(new_legend_test.llb with main.vi as main function). When I try to
control the input selected values again I get them back but I don't
understand why they have no effect on the legend of my waveform chart.
Could somebody explain me what I m doing wrong or show me how to get a
correct legend with desired plots? Thank by advance for your assistance.
N.B.
The
both attached data are saved with labview 2009.
Sincerly,PrinceJack
Attachments:
old_legend_test.llb ‏65 KB
new_legend_test.llb ‏65 KB

Hi
princejack,
Thanks for
posting on National Instruments forum.
The behavior
you have is completely normal. You can control the number of row displayed in
the legend and this rows are linked to the data you send to your graph. Thus,
if you have 3 arrays of data, let say chan1, chan2 and chan3, you can choose
which data you want to display in your graph using the property node (Active
plot and visible). But for the legend as you send 3 plots there is an array of
the plot name [chan1, chan2, chan3] and you can display 0, 1, 2 or 3 rows of
this array but you cannot control the order in this array! So, to be able to
change this array you have to only send data you need to you graph. I'm not
sure my explanations are clear so I have implemented a simple example doing
that.
Benjamin R.
R&D Software Development Manager
http://www.fluigent.com/
Attachments:
GraphLegend.vi ‏85 KB

Questions on Labview 8.5 for Linux edition

Hi All,
I have some questions about LV 8.5 Linux edition:
1, Does it follow the GPL rules?
2, Which main distributions it supports?
3, Why I cannot download an evaluation edition?
Thanks.
David

DavidLee wrote:
Hi All,
I have some questions about LV 8.5 Linux edition:
1, Does it follow the GPL rules?
2, Which main distributions it supports?
3, Why I cannot download an evaluation edition?
Thanks.
David
1. LabVIEW is closed source and therefore the GPL does not apply to LabVIEW itself. It does make use of some external componanats that are under the GPL such as the kernel itself and the MESA library which is
2) look under www.ni.com/linux/support.htm#1. basically most recent RPM distributions should be fine but for non-RPM versions it installs reasonably well on recent systems. Got it to run on Ubuntu Feisty without real problems after installing RPM package support.
3) There isn't one. Since there is no license manager for non-Windows versions NI can not make an evaluation version that can be activated through a license key. This would require a separate build with reduced functionality to release as evaluation version, and the sales for LabVIEW for Linux do not justify that extra expense.
Rolf Kalbermatter
Message Edited by rolfk on 12-24-2007 10:01 AM
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

A Question about LV Database Connectivity Toolkit

Hello everyone!
I have a question about using LabVIEW DataBase Connectivity Toolkit 1.0.2 that eagerly needs your help. I don't know how to programmaticlly create a new Microsoft Access(.mdb)file (Not a new table in a existing Database)using LabVIEW Database Connectivity Toolkit1.0.2. As you know, usually we can set up the connection by creating a Universal Data Link (.udl) file and inputting the path to the DB Tools Open Connec VI in the LabVIEW DataBase Connectivity Toolkit. However, searching a table within an existing database containing a great many tables is a toilfulif job. If I want to use a new DataBase file with the date and time string as its name to log my acquisition data in each measurement process, how to do? I am sure someone of you must can resolve my question, and thanks very much for your help.

I don't know what your real design considerations are here but, from I understand from your post, this is a really bad way to go about the process of logging data -- IF you want to be able to do significant ad hoc or stored procedures analyses after it has been collected. Using separate MDB files for data that ONLY differs by one field (namely that date) is not the most efficient way to organize it. What would be much more efficient would a joined table including the date and a reference ID of some sort for the various measurements that were done. That way your stored procedures for looking at ALL measurements of type X would be very simple going across ALL dates. Making such a comparison across multiple MDB files is a much more challenging process AND doing the original data collection in that way doesn't really gain you anything.
Generally, if something is difficult to do in the DCT (Database Connectivity Toolkit) it's because it's a "not good thing" to do within MDBs. I know that others probably disagree with that but I've worked with Access since it's initial release and other RDBMs prior to that both through compiled tools, Unix scripts, etc. You may, of course, still choose to proceed in the way you've described and that may work excellently for you.

Question about Lego Mindstorms Capabilities

Hello, thank you for reading my question!
I am currently working on the creation of a teleoperated robotics lab. for a introductory robotics course. I wish to allow students to control a labyrinth-solver robot via Labview, with the Lego NXT toolbox. A computer server will be connected to the Lego via Bluetooth, and the student communicates with the server via a web browser VI (a web published VI). I am interested on the Lego Mindstorm platform but I wanted to ask some questions about its software capabilities:
*Is it posible via a web VI interface for the student to load a program onto the Lego Mindstorm? My idea is to allow the student to load a VI (or the equivalent of a LEGO NXT ".exe")onto the server, and the server to load the program to the Lego. The Web VI already has some parameters the student can change a simple program execution (see [1]), but I also wanted to give the student the chance of loading their own program for more complicated algorithms.
Thank you in advanced for your time and patience!
[1] Maze Solving Algorithms
http://en.wikipedia.org/wiki/Maze_solving_algorithm

thats the exact error, could it be something of the automathic update of the driver once the joystick was conected through the usb?

A question about comments

Hi, all,
I have a question about the comments:
Program function comments should be included on the block diagram or Front panel, or both. Thanks.

Many good things have already been mentioned.
For the Front panel, there should be a clear distinction between toplevel VIs (or any subVIs where the user must interact with the front panel), and subVIs where the front panel is only of interest to the programmer. The needs here are quite different:
User Interface VIs
The front panel should be clear and easy to use. All "help" elements, tip strips, etc are geared towards the end user. The icon is irrelevant, because it is typically not even shown. Everything of interest to code maintenance should be on the diagram.
subVIs
Here, the front panel can contain a description of what the subVI does, who created it, company and copyright information, version information, limitations (e.g. input A must be >0), URLs or literature references to the algorithm, etc. (Have a look at any of the openG tools!). The "VI properties...documentation" section should be populated. The icon should be descriptive. All controls and indicators should have intuitive names (not just "Numeric 4", or "Array" )
Comments specific to certain areas of the code should be placed where they apply, especially if the code uses some exotic algorithm that would make the code hard to interpret.
Use a programming style that is self-documenting. (e.g. Don't unbundle the error cluster check for "equal zero" to switch a case statement. Wire the error cluster directly to the case so you'll get a red/green error case structure. Much more obvious!)
If these are proprietary VIs with password protected diagrams You should split the comments: Anything of interest to the non-privileged user goes on the front panel, anything else on the diagram.
In the end, it does not really matters where you place the comments as long as they are easy to find later and still make sense to somebody else 10 years from now. Message Edited by altenbach on 05-30-2005 01:13 PM
LabVIEW Champion . Do more with less code and in less time .

Question about octave analysis

Hello !
I have the following question about the octave analysis vi's.
When the single octave analysis is made, shouldn't there be 3 bands below 100 Hz ?
According to the octave analysis subvi, the bands should be located at 16, 31.5 and 64 Hz.
I've tryed to make a comparison between octave, 1/3 octave and 1/24 octave.
It seems there is no difference.
I'm running LabView 8.5.1 with SVT 6.0 on windows 7 professional.
This is not happening. See the attached vi for an example of the problem.
P.S. : The file Engine runup is a sample. please rename extension to WAW.
Thank you.
Attachments:
Engine Runup (mic).wav.jpg ‏235 KB
Sonometru.vi ‏330 KB

I also have problems with octave analysis, I'm making the acquisition of a pink noise from my audio card and checking the response curve through an analysis of octaves, to obtain a flat response curve, I need to set a number of samples of at least 88200, but this way I can not get a high-speed acquisition, only about one aquisition/second, putting a value of 2000 samples the speed is adequate, but the response curve in octaves loses response below 1000 Hz gradually until around 20 Hz is practically nil, I need help please.
best regards.

A question about cluster

Hi all,
I have a question about the usage of cluster. I create a cluaster
which includes three indicators on the front panel, but I can't use
unbundle function on the diagram. If I change the indicator to control,
it works. I didn't find on the manual that the unbundle function only
accept cluster of control as input.
Thanks for your help!
Regards,
Tao

This is because of the way dataflow programming works. It probably didn't
explicitly mention.
Labview has data sources (controls, inputs) and data sinks (indicators,
outputs). Unbundling accepts cluster as input and outputs the individual
pieces of data. Similarly bundling accepts individual pieces of data as
input and ouputs a cluster. So logically your cluster must be a control
(input) for unbundling, and an indicator (output) for bundling.
If I'm misunderstanding the question or oversimplifying the problem email me
or post again.
-joey
"tsong" wrote in message news:b11154$qmq$[email protected]..
> Hi all,
>
> I have a question about the usage of cluster. I create a cluaster
> which includes three indicators on the front panel, but I can'
t use
> unbundle function on the diagram. If I change the indicator to control,
> it works. I didn't find on the manual that the unbundle function only
> accept cluster of control as input.
>
> Thanks for your help!
>
> Regards,
>
> Tao
>
>
>

Question about Local Variables (Multiple answers welcomed!)

A couple of questions about Local Variables
1. Programmers always say: “Do not abuse of Local Variables”. I’d like to know, when and where Local variable are most efficiently used?
2. If I have to create a couple of local variables, is there anyway to “clone” them without going through the repetitive “create/local variables” mouse click each time? (When I try to copy and paste, it creates a new variables instead of the one that I am trying to reproduce)
3. Which is faster in execution: Updating a variable through a) writing to property node/value or b) through local variable
Everyone’s input is welcomed, so if this question is already answered, please
feel free to add additional comments/answers!

1. Use Local Variables in user interface code and no where else. The only exception is using a local variable of a cluster output to define the datatype for a bundle by name node.
2. You can drag copy them then right click to get to a menu of all the currently defined controls and indicators on the VI.
3. B. The problem with A is that it forces a thread switch to the user interface thread--which can take time if you aren't already in it, and it's a very convoluted process under the hood. NI's advice never update indicator values through a property node unless you absolutely, positively can't figure out some other way of doing it.
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

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