RE: Redrawing XY Graphs
Dear list, This wish has been a longtimer. The first time I requested this feature was in LV 2.2. We now happily arrived at 7.1 but this useful feature is still not there. Not enough requests could be the the answer from the developers. You can do these kind of things with the picture control but then again a picture control is not graph and we all love graphs and charts, don't we. It still would be REALLY NICE to have one day an XY-Chart. After all we have Waveform Graphs and Waveform Charts and to me it seems to be just natural to have XY-Graphs and XY-Charts too. Probably we have to wait until LabVIEW 10 or LabVIEW X as they may decide to name it then, many years from now maybe I will be sixtyfour then. Happy wireworking yours Urs Lauterburg Physics Institute University of Bern Switzerland I would also like to know the answer for that incase anyone replying separately to John. Thanks Shankar Shankar K. Subramanian TSS ESG Northboro RD Center Saint-Gobain -Original Message- From: John Brohan [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 11, 2004 2:33 PM To: [EMAIL PROTECTED] Subject: Redrawing XY Graphs Redrawing XY Graphs Is there any technique to add new points to an XY graph without re-drawing the whole thing? Dropping points does not seem to be an option in this application. Yours Sincerely John John Brohan National Instruments LabVIEW expert in Montreal Traders Micro We connect all sorts of things to computers 317 Barberry Place DDO Montreal PQ Canada H9G 1V3 Tel (514)995-3749 [EMAIL PROTECTED] http://www.TradersMicro.com/Index.htm
Continuous Waveform 1Hz
I need to generate a continuous waveform (sine, square, triangle) that is less than 1 Hz. I have tried doing it manually by sending out a 100 point array, one point every X ms based on the frequency setpoint. For example if the frequency is 0.1 Hz I send a point out every 1 ms. The problem I have is I need 0.05 Hz resolution (customer specification). It would be nice to use the Analog output continuous waveform VI supplied with Labview but it doesn't work with anything less than 1 Hz. Any clues?
Re: Linking .vi's
Have you tried making the LED you want to illuminate a Global variable?
Re: VISA serial communication in LV 7 application
Ah, yes, serial communication is supposed to be simple, but it is often frustrating. I have done a fair amount of this, but none under LV7. Whether or not you get errors depends on the nature of the communication. For instance, suppose you send a request for status information to your serial device. Maybe you send a sts to the device. If there is nothing to receive your command, you will not get an error in your code. You will in fact send sts to the device, even though your device isn't hearing it. If you do a serial read each time you make this request, then you should get an error. If no device is listening to your command, then you should get a serial timeout error. The error reporting might have something to do with the new automatic error reporting features in LV7. Make sure that you are not using only the automatic error handling feature, which is unavailable in the run time engine. Before you conclude that the code is fine just because it ran on your development machine, make sure that it is even possible for your code to generate serial communication errors. Generally, it should be possible, but based on the limited information that you provided in your question, I have to issue this caution. Assuming your code can indeed generate serial communication errors and you are monitoring those errors properly, then you should double check the serial port resources. Make sure that your target control machine is defined according to the code you wrote, e.g. all of the settings, including the visa resource name should be identical. If you attach your source code, or perhaps a reduced example of your code, I'm sure we could get to the bottom of it quickly.
LabVIEW crashes when I paste to the diagram
When I paste a part of one diagram to another, Labview 7 crashes with The thread 'Win32 Thread' (0x910) has exited with code 0 (0x0). Unhandled exception at 0x0084d46e in LabVIEW.exe: 0xC005: Access violation reading location 0x8168592c.
Re: i am able to get color images in the continues shot but when...
vicky, I am unfamiliar with the lv_vfw.llb, and have not used it before. However, I noticed that you stated that you are able to grab in color, just not snap in color. If this is the case, why not just perform a grab and then extract a single buffer from this grabbed data, which would likely be in color? This seems like a possible solution to the issue that you are seeing. Other than that, I really don't know enough about the lv_vfw.llb to be of much help on this issue. Hopefully another member of this forum will be able to assist you with this software. Regards, Jed R. Applications Engineer National Instruments
Re: Error -1073807246 when trying to control a circulator in Labview via RS-232
The timeout value was just set at the default. How do you know how long your stream of data is? The purpose of my application is to input a setpoint temperature to the refrigerator/heating circulator and also read what temperature the circulator is actually at. The circulator recognizes certain commands that is inputted from the computer. For example, to set the setpoint temperature to 25 deg C, the command is: out_sp_00 25.0 return So I have set up out_sp_00 as a string constant and the setpoint temp is inputted through a string control. Also, I used a carriage return. All of these are then concatonated together. So what would the size of this data stream be considered as? Do I even have the right idea of inputting this command or have I done things the long/wrong way? Thanks for the heads up if a timeout occured when reading
Re: SCR Phase Angle control
Greetings Nick: You should be able to get good results with your technique. (You're essentially doing a poor-man's Direct Digital Sythesis, when reading a pre-constructed table like you are doing) Another way to do this is generate a sine wave, using one of the sine generator vi's and then run it through a series of comparators (use comparison primitive) each with a different threshold. Add the values of each comparator output, and voila, this is your stepped wave. In this manner, you are simulating a flash A/D convertor. Another way to do this, is to run a square wave generator (say at 400Hz) and MULTIPLY this by a sine wave at 50 Hz. This will give you a Sine wave modulated square wave, (or vice versa, since mathematically, they are identical!) Eric
Re: memory management and style
Thanks for responding, Shane. All of that was very informative. I still have some comments: 1) Could you elaborate on the statement references [force] everything through the GUI thread? This kind of makes sense to me, but I haven't found much info on the web besides using references for non-GUI stuff is not recommended. I have personally noticed that sub-VI's that use refnums and property nodes do take more resources. 3) Re: OO Having interfaces (abstract classes) would be nice, from a polymorphic point of view. I know LabView has polymorphic VI's, but do polymorphic VI's distinguish between *different* cluster type def's? A more important problem is that you can't easily make an array of different (but related) type-def's. That takes away a lot of the elegance of polymorphism. Here's a real example: I have 3 different types of pumps that have different serial protocols. They all have basic functions like pump and stop. In LabView, I have to call the pump.vi for each different type of pump, and I can't have all the pumps in the same array. In Java, I would create an abstract class called PumpObject, and each subclass would HAVE to have a pump function. I could write the classes Pump1, Pump2, and Pump3, each of which is a subclass of PumpObject. So then, in my main function, I could have an array of PumpObjects, and tell all of the elements to call their pump functions. Each type of pump would know what to do, even though they all handle their serial communications differently. This would take all of 4 lines of code. I realize that, with enough polymorphic VI's, case statements, refnums, or variants, I could work something similarly out, but most people would not be able to work out such a hack.
Re: Looking for ready-to-use indicator that looks like a horizontal-platform panel in an airplane
This can be done, but it will take some work. There are two approaches. You can use the PICTURE functions, and build the diagrams up a layer at a time. (Your PICTURE vi's are loop through, meaning you can take the output of one, say a grid, and input it to another, to overlay a pointer, for example) Another way, probably more labor intensive, is to use the property node to modify a button of some kind ( color, shape, etc) to make it appear like the indicatory you want. You might want to look through the NI database to see if there is anything similar that someone has written that you can embrace and extend to fit your application. In the meantime, you have given me a personal challenge! I think this would be a good extra-curricular project for me :) Eric
Re: Is it possible to set the current value as default while VI is running?
Thanks Ed Here i want to add something. Rightnow i am doing the same thing what you said in your mail. I agree with your statement. But i am seeing some properties in property node which talks about make current value default. From this how will i do that? Is it possible to do with VI server?
Re: memory management and style
thanks for the comments, ryan. It's always nice to hear from the people who develop the software. 1) It seems to me that allowing people to pass pointers to complex data structures would allow for more efficient memory management. I know about refnums, but Shane and others seem to imply that refnums/property nodes come with unnecessary GUI overhead. I hate pointers as much as anyone else, but being able to pass by reference without overhead would be HUGE. Is there a way to do this? 2) The avoid local variables when possible bit is news to me. But I get the point ;) 3) as far as I know, the GOOP projects use refnums, which are subject to the same overhead constraints as mentioned in (1). 4) I think the problem with college courses is that most professors who design course curricula know about LabView, but they don't use it themselves -- their graduate students do. I've seen certain TA's make LabView instruction a pet project, but the novelty of G means that most students are happy to get to the point where they don't have broken wires everywhere (believe me, there's lots of swearing on LabView lab days). And most students are more worried about running their experiments than programming.
Re: multiple plotting but not with static inputs but using a control inputs once.
hi, i shall explain my problem , i want to plot the SCR char with the gate current applied (without gate current applied is done n working fine) so , for a comparative study of the effect of gate current i want to plot multiple curves , at the moment i m prompting the user to enter the value for the gate current and this controls further , there is a dial control for the forward voltage etc..., at the moment its plotting only once .so that is my problem regards tanisha
Re: Graphs placed over indicators causing slow operation.
- Original Message - From: John Brohan [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, May 10, 2004 7:19 PM Subject: Graphs placed over indicators causing slow operation. Hello I have an XY graph which is visible sometimes and not visible at others. It seems important what it is covering. For example if it is covering another graphic with a changing display the whole process is slowed down. If I remove the covered graphic or make it not visible speed improves.. There are several indicators with changing values that are covered by my graph. Is it better to make them invisible or make their values not change or is there some better way Tab controls for example. It's long known that having indicators underneath transparent graphs causes quite a slowdown. Is that your case or are the indicators unseen until you make the graph invisible? I guess the controls aren't intelligent enough to know if they're really visible if the visible flag is set true and the window is open and the same performance hit is applying. If you're using the graph to hide controls until needed then the tab control is the way to go. Manually showing and hiding controls is a pig to do in the first place, and a pig for you or someone else to maintain. You can hide the buttons of the tab control if you want to present a wizard style interface. -- Dr. Craig Graham, Software Engineer Advanced Analysis and Integration Limited, UK. http://www.aail.co.uk/
OpenG Coding Challenge - Remove Backspace
I really wonder who will win the contest... /Andreas
Re: Cannot locate menu for the PID Toolkit
Normally, it is located on the left bottom corner of the functions palette
Re: Matlab Scripting VI/Need help
Hi Olga, Finally, I decided to execute my Matlab program siparatly from LABVIEW acquisition program.Since, when matlab P. is long, the time of calculation by matlab is so long as compared with the time required for LABVIEW execution. So, it is not possible to execute both deux program in the same espace of time. But, if you have one syclic acquisition avec low frequence, it is possible! Regard
Re: run time menu in remote panel
Hello, yes, I have edited the run time menus, and they work fine when the VI is run from within labview, or built into an application. The trouble comes when I view the panel remotely using the web server. None of the run-time menus are there. rgds neil
The NI service locator is not running
Running under Linux, after having installed all packages, I still get the above responce, when I click the Find examples... button.
Continous acquisition on 800MHz, W_XP, with 6025E - has a problem on 200kS/s
Hello I try to continously acquire data from two channels of PCI-6025E in Win XP, stand alone LV7.1 application. It works well on 100kS/s, but it got real difficulty with going to maximum speed 200kS. I set buffer to 1M, which is enough for 100kS, but soon is getting overloaded in case of 200kS and some often software triggering. But even without triggering it gets problematic. I found out that the 10-30kS per iteration is the optimal setting. The question is whether it is my application fault, and this setup should easily run on this PC, or I am close to the limit. Thank you in advance Pawel
how can I display on a string the symbol omega (ohms)
how can I display on a string the symbol omega (ohms)
how can i transform lowercase char in uppercase char automatically
I would like that when you write lowercase char in a control string these char be converted automaticaly in uppercase char in this string
Software Programmer opening in Cary, NC
My apologies for intruding on the list, but we have an opening for a software engineer. We are a National Instruments Alliance Member in Cary, NC (Raleigh-Durham area). The qualifications for which we are looking are LabVIEW programming skills (a must) and text-based language capability (secondary in interest). Please send resumes to: Craig Borsack G2 Test Measurement 8000 Regency Parkway, Suite 405 Cary,NC 27511 phone: (919)481-1530 x302 [EMAIL PROTECTED]
Re: Peut-on lancer une acquisition dans un serveur TCPIP sans stopper la communicationTCPIP?
Bonjour, Quel outil utilisez vous ? LabVIEW,CVI,Visual ...? Une solution consisterait =E0 utiliser deux boucles en paral=E8lle sous LabVIEW ou deux thread si vous utilisez le C ou C++ et mettre en oeuvre un m=E9canisme de synchronisation tel que la notification. Par exemple en LabVIEW, une boucle sera =E0 l'=E9coute des vos trames TCP/IP si cette trame concerne une requ=EAte d'aquistion vous pouvez envoyer un message de notification =E0 la deuxi=E8me boucle qui va se reveiller =E0 ce moment l=E0. Il existe plusieurs exemples sous LabVIEW. J'esp=E8res que ces =E9l=E9ments vous permettront d'avancer. Sinc=E8res salutations. Salissou ISSA Ing=E9nieur d'application National Instruments France
Re: Mitutoyo MUX2, Digimatic Micrometer heads and Labview7
Ok first go through the first list I posted here and work out what you are missing. Post a list of what you are missing. i.e do you have the manuals for the MUX2? There is no reason that I am aware of that the student edition won't do. At the moment I have not fully transferred to 7.X so 6.1 would be good also. Anyway the reson that there is no driver is mainly becuase people in production processes (where these things are used in volume) need validated statistical tools. No one has written a complete fully approved automotive statistics tool in Labview (I believe), hence no driver. As the approval process is expensive, long and tortous you start to understand why. To get you going if you have all the cables you should start with the Trerminal Emulator. (I assume Windows here). Set 9600bd 7 data bits, 1Stb, No Parity - no handshake. Press the instrument 'Data' button and the instrument should send a measurement to the Terminal program. You may need to 'tinker' (my first choice was refused by the msg bd) with the data rates and handshake to get the data onto the terminal program as the handshake could be affected by the wiring on the cable between the MUX and the host and the data rate could possibly have been changed on the MUX. You quickly find out that the number of combintations is awesome - Hence the requirement for the manual. So go through the list I wrote and tell me what you have or not as the case may be.
[W] off topic - running BATch files as scheduled task under XP
Friends I used to run a very simple batch file that appends one file on to the end of another. It was a scheduled task in the Task Manager under W98. Now I have XP Pro SP1 and I can execute the batch file manually any time without errors but when I execute it from the Task Manager, whether I let it run at the proper time or right-click and select Run, I get a dialog box that says c:\windows\system32\svchost.exe The NTVDM CPU has encountered an illegal instruction... If I comment out everything, I still get the same error. The actual DOS window is completely blank meaning that probably nothing was executed. Any ideas? R. Glenn Givens P.Eng. Innovention Industries Inc. Burlington, ON, Canada www.innovin.com
RE: OpenG Coding Challenge - Remove Backspace
I hav just returned from a week-long trip and will be moving forward with the judging. Regards, -Jim Kring -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andreas Nilsson Sent: Tuesday, May 11, 2004 12:27 AM To: Info-Labview Mailing List (E-mail) Subject: OpenG Coding Challenge - Remove Backspace I really wonder who will win the contest... /Andreas
Re: Multiple Waveform Graphs
In the case of the former do I use much more memory or slow down the execution of my program more than in the case of the latter? In part of your question you call the control a graph, and in other parts a chart. The answer depends a bit on which you are showing and hiding. Graphs only show the most recent data written to them, charts retain and show history. Neither the graph or chart will have much overhead receiving data while hidden. On the otherhand, it isn't zero either since they will at least be doing a data copy so they can draw with correct data when shown. It will be easiest to send the data all the time since otherwise, you will need to send fresh data when showing the graph. If dealing charts, not only will you need to update the current data, but the history will be old. You will need to clear or write the history. If it doesn't cause a problem, write to them always, but if you can measure a problem or have spare time on your hands, add code to make the update conditional and deal with the data when being shown. Greg McKaskle
Re: Is there a way to clean up all the wires at once?
Hi Open the Block Diagram of the vi named Open Block Diagram Refnum.vi and read the note I put in here. It says Exposed in several location: ex: ..\National Instruments\MAX\Assistants\LVCGen\LV70\mxwScript_ClusterConnector.vi For more scripting utility and exposed primitive go to the LAVA forum and check this Sub Forum: http://forums.lavausergroup.org/index.php?showforum=29 Cheers PJM
Re: Is there a way to clean up all the wires at once?
Sweet VI Good job. how did you get the ref to the block diagram. I have been looking for it.
Re: Update LabView 6.1 to 7.0; error 1003
Hi, the error 1003 normally indicates a not runnable subVI. It wonder if the VI is running under LabVIEW 7 or if the error only occures when building an executable? Perhaps you can post your VI, so that I can check it on my computer? A few weeks ago, I had a similar problem running a LV6.1 VI under LV7. At that time the error was that the connections of a VISA-VI had changed, so that I had to wire one additional connection in LV7, but not in LV6.1. regards, Peter Weber NI Germany
Re: The NI service locator is not running
Hi Nanorui, Could you tell me a little more about your setup? Do you happen to be running RedHat with LabVIEW 7.0? To my knowledge, this issue has been fixed in LabVIEW 7.1. You might also be seeing something similar if you installed LabVIEW into a non-standard location. If you run LabVIEW as root, does it work as expected? Also, even though you get that message, are you still able to browse the examples and open them? Or does the example finder not come up at all? Let me know what distribution, kernel, and version of LabVIEW you are running and I'll try to figure out what is going on. -- David Duffey National Instruments
Re: Cannot locate menu for the PID Toolkit
If you have multiple copies of LabVIEW on your computer, see if it was installed to another version. If so, you can uninstall and then reinstall making sure that the installer is pointed to the correct LabVIEW folder.
Re: Labview code for Compumotor 6000 Indexer
We don't have a driver for this instrument, and I wasn't able to find any LabVIEW drivers by the manufacturer, so you'll probably need to program it using the user manual for the instrument. I think the user manual you need is probably found here: http://www.compumotor.com/manuals/6000s/6000PG.pdf From a LabVIEW standpoint, you'll just use VISA Write to send the commands you find in that manual. You could use an event structure, or case structures within your loop to get input from buttons which would control the motion. Best of luck, Ryan K.
RE: [W] off topic - running BATch files as scheduled task under XP
I think that this might have to do with your Shortcut if that makes Sense.. I had something similar happen, and I deleted my Desktop Shortcut Icon and made another, and the issue went away. WinXP also allows by right clicking and selecting properties a compatibility mode in which the programs/processes should run. I can't guarantee this will fix your issue, but its a simple experiment. The problem is actually an issue with a Microsoft support file rather than with your Batch file. I think this issue is addressed by Microsoft in an article at the following link: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q245184 HTH, Rick Mahoney Equipment Test Design Lockheed Martin Corp Syracuse, New York 13221 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of R. Glenn Givens Sent: Tuesday, May 11, 2004 10:32 AM To: LabView Discussion Group Subject: [W] off topic - running BATch files as scheduled task under XP Friends I used to run a very simple batch file that appends one file on to the end of another. It was a scheduled task in the Task Manager under W98. Now I have XP Pro SP1 and I can execute the batch file manually any time without errors but when I execute it from the Task Manager, whether I let it run at the proper time or right-click and select Run, I get a dialog box that says c:\windows\system32\svchost.exe The NTVDM CPU has encountered an illegal instruction... If I comment out everything, I still get the same error. The actual DOS window is completely blank meaning that probably nothing was executed. Any ideas? R. Glenn Givens P.Eng. Innovention Industries Inc. Burlington, ON, Canada www.innovin.com
Linking .vi's
Sorry if this is an stupid question, but I was wondering if someone could tell me how to do the following: I'll be running two .vi's simultaneously during some work I'm doing and rather than having both front panels up at once I'd like to link them so that when a particular property being monitered by one .vi goes outside of a given range of values, it causes a LED to illuminate on the front panel of the other, alerting me to the problem. Is this possible? If so, what is the best way to go about it?
Re: MODBUS
Hello, It is possible to command a Modbus device with LabVIEW. You will need some sort of OPC server that speaks Modbus. Once you have that, you can use the Datasocket VIs in LabVIEW to communicate with your Modbus device (via the OPC server). If you do not have an OPC server, National Instruments does sell an OPC server that supports Modbus. This OPC server is called the Industrial Automation OPC Server (http://sine.ni.com/apps/we/nioc.vp?lang=USpc=mncid=4584). So as you can see, the process is not too difficult. Once you have installed the OPC server and configured it to talk to your Modbus device, the Datasocket API in LabVIEW will be able to connect to the Modbus device via the OPC server. Hope this answers your question. Please let us know if you have any additional questions on this. Have a nice day! A. Saha Applications Engineering National Instruments
Re: page fault in nipalk.sys when writing large file , system crashes
Hello jcnoble, If you experience a crash in any National Instruments software component (if you look at the Properties for nipalk.sys, you should find a Company tag that says National Instruments Corporation or similar), I would first recommend upgrading all software to the latest available version -- see http://www.ni.com/downloads/ Drivers and Updates Current Software Versions. You may also want to search the NI KnowledgeBase at http://www.ni.com/support/ for patches and Service Packs that may apply. If after upgrading, you continue to experience failures, I would strongly recommend that you contact National Instruments Support via phone or email at http://www.ni.com/support/. To expedite your support, please have all of the details regarding your issue handy. This includes the crash information (bugcheck, fault, stop code and parameters), context information on how to reproduce the crash, memory dumps, installed hardware (computer brand/model, NI devices, third-party devices), and installed software (OS version, OS Service Pack, NI software, and third-party software including the versions). I am confident that our Applications Engineers can resolve your issue in a timely fashion and make your application a success. Sincerely, Jeremiah -- Staff Product Support Engineer -- Systems Software National Instruments -- http://www.ni.com/support
Re: Cannot locate menu for the PID Toolkit
Hi Jeremy, Thanks for your reply. The LabView installation was the first install on a brand new PC. I did some poking around yesterday with Windows Explorer and was able to locate the PID conponents directories. The PID control blocks show up with Explorer, but are not visible among the regular group of control blocks. (graphs, knobs, etc.) Is there a way to bring the PID control blocks into the group? That would get me going. It's also strange that the Fuzzy Logic help menu shows up under the main help menu but not the PID help. Any suggestions on that? Thanks, Art
Re: Génération de signaux !
Pour le tableau c'est bon j'ai trouv=E9 cela venait en fait d'un mauvais =E9chantillonnage; Merci
Re: Why is 2nd While Loop in State Machine generated by State Diagram Toolkit?
Sacha gave a valid answer but let me try to help. 1st I do not have LV 7.1 on my machine yet so I can not open your example VI. 2nd ...why is 2nd While Loop [and Enum to Interger and status's Enum constant] in main State Case? The small while loop inside one of your states is the logic used to decide which state your application will transition to next. If your design only has the default transition, this loop does not do much. If you have a state that can transition to more than one other states, that small loop does the decision making to decide which state we got to next. Now if you have a state that can transition to one of many other states, AND the conditions (see below) are satisfied for more than one of the transitions, you can define which of those states wins by defining the order in which those conditions are checked. So... The small while loop determines which state you go to next. It only makes a difference in states that have more than one state that they can transition to. 3rd When you have a state in your design that can transition to more than other state, the SD Editor will create a new case in the little while loop for your new transition. When it does, the SD Editor will leave the boolean tunnel un-wired. You can then insert the appropriate LV code that will return a true when the condition is met. When I am designing apps using the SD Editor, I will draw-up the design and leave all of those tunnels un-wired until I think I have something worth checking. At that time I will then copy the name of the transition from the SD and then click on the transition arrow in the SD. This will cause the block diagram to show the code where that transition is located. I will then right click on the output tunnel and do a create control. When the new control is created, I will then paste the transition name I copied (see above) into the newly created button. I will continue this process until I have fixed all of the un-wired booleans. After the VI is no-longer broken, I will have a bunch of booleans on my FP with names that match up with the transisions. Now it time for some fun! I then put the SD in execution highlighting and watch how the program flows using the boolean on the front panel to test all of the code. This serves a number of purposes; 1) I can think through all of my logic before getting into the low level stuff. 2) The FP booleans serve as reminders that I have to write code to replace the buttons. 3) I think its interesting to watch my designs in action. If all is OK at this point, I am ready to develop code for each state. Sorry I drifted off subject a little there. Back to your Q! 4th The small while loop allows each state to have a unique set of transitions. If it was outside the individual states (as you suggested) the transition would have to be shared. I hope this answer along with Sacha's answer is valualbe to someone. Ben
Re: Synchronisation PCI-4472 PCI-4474 with DAQmx
Bonjour, Les cartes PCI-4472 et PCI-4474 ne sont pas dans la liste des cartes compatibles avec l'exemple Multi-Device Synch-Shared Timebase-Cont Acquisition.vi. Ceci peut expliquer pourquoi le noeud de propri=E9t=E9 renvoie une erreur DAQmx. Vous pouvez utiliser l'exemple Multi-Device Sync AI Shared Timebase Trig DSA qui a =E9t=E9 d=E9velopp=E9 sp=E9cialement pour les cartes DSA (e= t donc les PCI-4472 4474). Cet exemple permet de faire de l'acquisition simultan=E9e finie avec d=E9clenchement commun. Pour faire une acquisition continue, il vous suffira de param=E9trer le NI-DAQmx Timing =E0 Continuous samples et d'int=E9grer le NI-DAQmx Read dans une boucle While. Cordialement.
Is it possible to set the current value as default while VI is running?
I have one numeric control in frontpanel. I am dynamically changing the value of that control. Once if i quit the program and if i opened again what ever value i entered before quitting the VI, it should appear as a default value. Is it possible to set the current value as default while VI is running? Note: I don't want use another VI to make this value as default.
Array into dll
I built a dll in LV 7. One of the inputs was an array of strings. LV
created the following typedef for this input:
typedef struct {
long dimSize;
LStrHandle elt[1];
} TD2;
typedef TD2 **TD2Hdl;
The function prototype generated by LV is:
void __stdcall AddRow(TD1 *errorInNoError, TD2Hdl *TestResult,
LVRefNum *WordTableIn, LVRefNum *WordSelectionIn, TD1
*errorOut);
The question is to call this function, what do I have to pass into the
dll from LV? I've tried several ways and it keeps crashing. When I
create the dll, it doesn't give me the option to define the input as
an array, it just creates the typedef. So when I configured the dll,
I chose Adapt to Type. This didn't work with either Handle by
Value or Pointer to Handle. If I configure the input as an Array,
there is no string type listed (uint32 maybe?)
TIA
Bill F
Re: How I can change file time date stamp?
Hi fbrutus, yes, I care! Your hack certainly works but pretty cumbersome. I was looking for modifying a text file but I want the original date not to be overwritten. I want to be able later to sort my measurement data by the original date. If LabView isn't capable of doing this task, isn't there any command in DOS which can be called from LabView? Thanks for help, Tilman.
Redrawing XY Graphs
Redrawing XY Graphs Is there any technique to add new points to an XY graph without re-drawing the whole thing? Dropping points does not seem to be an option in this application. Yours Sincerely John John Brohan National Instruments LabVIEW expert in Montreal Traders Micro We connect all sorts of things to computers 317 Barberry Place DDO Montreal PQ Canada H9G 1V3 Tel (514)995-3749 [EMAIL PROTECTED] http://www.TradersMicro.com/Index.htm
RE: Redrawing XY Graphs
I would also like to know the answer for that incase anyone replying separately to John. Thanks Shankar Shankar K. Subramanian TSS ESG Northboro RD Center Saint-Gobain -Original Message- From: John Brohan [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 11, 2004 2:33 PM To: [EMAIL PROTECTED] Subject: Redrawing XY Graphs Redrawing XY Graphs Is there any technique to add new points to an XY graph without re-drawing the whole thing? Dropping points does not seem to be an option in this application. Yours Sincerely John John Brohan National Instruments LabVIEW expert in Montreal Traders Micro We connect all sorts of things to computers 317 Barberry Place DDO Montreal PQ Canada H9G 1V3 Tel (514)995-3749 [EMAIL PROTECTED] http://www.TradersMicro.com/Index.htm
Re: Is it possible to set the current value as default while VI is running?
You cannot set a controls default value wihle the VI is running. Doing this requires the VI to be recompiled, and that cannot be done while the VI is running. The easiest way to do what you want would be to read the controls value as the VI shuts down and write it to a config file. Then when the VI starts up again, read the config file to get the last value and write it to the control. Check out the 'Config File' VIs in the File IO palette. These are made just for reading and writing to config files. Ed
Need popup tooltip over graph values selected by cursor...
I would like to do the following: Have an xy graph with multiple plots. The plots are values over time. The plots don't have sychronized or regular time updates which is why I used an xy graph which works great. I would like to have a vertical cursor that is free dragging that I can move horizontally. I would like to display a tooltip of the value of each graph just to the right of the cursor (x) and about at the level that the data point is at (y). Oh, I forgot to mention that each plot will have it's own y scale. Some possible but incomplete solutions. Solution 1) There's no cursor support built in to access a list of data points closest to the intersection of the virtical cursor and the plots. I thought about creating a cursor for each plot and locking them and then hiding all but one, making one free dragging and moving the others in response. This would at least get me my values, but it doesn't get me the xy location to display the popup tooltip. But the other major problem with this is that the times of each plot are not necessarily the same so the cursors can't stay synchronized. Scratch solution 1. Solution 2) Have single free dragging cursor. Get the bounds and the position of the plot...but wait, you can't get the position, only the bounds. You can get the position of the graph, but that is not the postition of the actual plot area. OK, so I moved the y scales to the right side and made that the plot area butted up against the upper left corner of the graph. That gets me the xy position. Now with the x scale, which there is only one, I can calculate the real x location for tooltip display. To get my actual values out of the graph, I have to take the cursor value which is time in seconds and search my data returning the points that are closest to the that time for each graph. If there is no value within some TBD distance, then I won't return a value for that plot. OK, I still have to calculate the y positions for the tooltips. I figured I'd just get the y scale values like I did for xexcept there doesn't appear to be a way to get all of the y scale values. There's y-scale which appears to be the first or current y scale and there's Active Y Scale, but that doesn't seem to do anything unless I'm supposed to make a writeable Active Y Scale property node and then immediately get the y scale values. So I think I'm stuck unless someone has some answers to solve the problem above. I suppose I could fake the scales with sliders like the old way of doing it and only have have one real y scale on the graph, but how many hoops do I need to jump over? If anyone has any ideas or knows of any more elegant solutions, or even an active x control that I could buy that has already solved this. Ultimately, in the end, if I can't do xy calculation for the tooltips, I'll just display them statically, but that is last resort.
Send path control or reference to path control to sub vi
Hello! I have a question of how to build correct labview structure. I have a path control in my main vi and want to check if it is correct in a sub vi. If not correct, ask the user for a correct one in the sub vi. I see two different options of how to do it and I think no one is realy good. 1. Draw a wire from the path control to the input of the subvi. The answer from the sub vi is connected to a local of the path control. This uses locals that I should not use. 2. Draw a reference from the path control to the input of the sub vi. In the sub vi change the value of the reference if path is not correct. No output is needed. Using reference you do not see where variables changes. How should I solve a problem like this? Please help me! TJ
Error -1073807246 when trying to control a circulator in Labview via RS-232
Hi, I'm trying to control an F32 refrigeration/heating circulator through LabView via an RS-232 cable but am having trouble. I keep getting the error - 1073807246 at property node (arg1) in VISA configure serial port. What does this error mean and how can I correct it? I have already specified the values for Baudrate (4800), parity (even), handshake (RTS/CTS), data bits (7), and stop bit (1). Thank you, Hung
Re: How I can change file time date stamp?
Some other links to free W32 versions of the UNIX btouch/b command: a href=http://unxutils.sourceforge.net/GNU utilities for W32/a a href=http://stevemiller.net/apps/Steve P. Miller's Win32 Console ToolBox 1.0/a I'm sure you'll find a few more if you do a quick web search.
