Re: Number of records in datalog-file
The file function EOF end-of-file returns the number of records in a datalog file when leaving pos and offset inputs unwired. Jean-Pierre Drolet www.avensys.ca - Original Message - From: Marco Tedaldi [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, June 21, 2004 6:37 AM Subject: Number of records in datalog-file Hello wiring people Is there an easy way to find out how many records there are in a datalog file? I've thaught about reading every record sequentially till an error occurs (or offset after read == filesize) but I think that's not really economical. Is there a better way to do this? Thank you in advance Marco
Re: Opening Acrobat Doc from LV
Sergey Liberman wrote: I am trying to open an Adobe Acrobat document (a manual for my program) from a LabVIEW program that will be deployed on a customer's computer. I was able to do it using System Exec with a command line like C:\Program Files\Adobe\Acrobat 5.0\AcroRd32.exe C:\Manuals\My Manual.pdf For that, I needed to find the absolute path to the Acrobat Reader on the target computer which I do by interrogating the Windows registry. It works fine, but I have a feeling that the same goal can be achieved by simpler means. Anyone can tip me on how to do it? On Win NT/2K/XP you can call System Exec (minimized) with cmd /C start c:\document\path.ext That will open any document (or application) with the default application associated with the file extension. On Win 95/98/ME it is command instead of cmd but I didn't test it. Jean-Pierre Drolet www.avensys.ca
Re: Wanted: #define
I think that the combo text box and the non-sequencial ring would make good symbolic constants on the diagram, allowing to display an item label and outputting a constant value with smaller footprint than a global. Unfortunately, in LV7 such diagram constants do NOT update from their typedef, keeping the same label and value as when they were put on the diagram. Is it fixed in 7.1? I agree that a better support for symbolic constants is needed for LabVIEW. I try to train my C programmers (and myself when I do C) to use symbolic constants for better documentation and maintenance (once one used #define K1 1024 which meant he didn't quite understand yet the actual purpose...). However it is more difficult to accomplish in LabVIEW. And the problem of defining symbolic constants is different than having no constants in the diagram at all. Symbolic constants are defined at compile time. Changes in constant values need recompilation. No constants on the diagram requires that parameters are assigned at run-time from a file or other resource that can be edited without recompilation of the source code. In this case, a Global VI populated with a INI file at initialization is a good technique. Jean-Pierre Drolet www.avensys.ca
RE: Time zones and time stamps
Lewis Drake wrote: However, there is still an area where NI could improve the time plotting capability. When the plot span is greater than a few days, the major tic marks are placed on the UTC values for midnight (and multiples of midnight for spans of a month or so) rather than the values for midnight local time. This results in weird, non-intuitive, major tic mark values to mark day boundaries, such as 8:00:00 pm (i.e. EST for midnight). I've just found that in LV7 you can correct this using the property Xscale.Range.Start and setting it to your local midnight instead of 0. Jean-Pierre Drolet www.avensys.ca
Re: Checking for running applications on remote machines
When the client app starts, it can try to open TCP connections to port 3015(Datasocket) and port 3363 (default TCP VI Server) to see if they are listened to by the server. If the connections fail the server is not running. If they succeed, close them. You could also set the server to reply to some UDP broadcast request when it is running. That allows to identify which servers are online on the network without knowing their IP.
Re: I want to acquire and display data from 89C51 micro controller using RS 232 port
Nice project, we do that all day long here. What is your problem exactly? The 89C52 has a UART you can use to write commands and read data. It is fairly straightforward to write a command processor for the uC and implement a command set. Is it the computer or the uC that generates the control pulses?
Re: Problem in receiving serial data!
UARTs (PC and uC) used to transmit data can be configured to transmit 5,6,7,8 or possibly 9 bits per transmission. You can't transmit 12 bits in a single operation. Either you set the uC to transmit 12bit data as 2 packets (2x6bits or 2x8 bits) or you pack 2x12 bits into 3x8bit packets. The 2x8bits seems to be convenient since you send data with the same packaging as internally used by the PC and the uC (16bit integers). You read 2 bytes from the serial port and then typecast the string to a U16. 3x8 would require a little bit swapping on both ends but would transmit the data faster if this is important. You read 3 bytes from the serial port and could typecast it to a U32 and extract 2 U16 with masking and shifting bits.
Re: Problem about SGL with temperature unit
Quote of the year:i 1 cannot be represented exactly in binary... /i That's too funny altenbach! How many bits of precision do you need to represent 1 exactly in binary?? =A6=AC
Re: Recursive Code Challenge
Salut, You are right. Formally, recursion can always be emulated with a data stack and a while loop. Using a recursive call, the data stack is managed automatically as data space is created for each recursion level. The cost in LabVIEW is efficiency. A recursive call makes the code more simple to design. The recursive nature of the code is explicit which is not the case with a while loop. Other than that, there are no clear advantage for the recusive call. Jean-Pierre Drolet www.avensys.ca - Original Message - From: Dominic Lavoie [EMAIL PROTECTED] To: Info-LabVIEW [EMAIL PROTECTED] Sent: Friday, June 04, 2004 9:15 AM Subject: RE: Recursive Code Challenge Salut. Could someone explain in a simple way what are the advantages of making a function recursive instead of just making the data recursive(arrays or strings) and building one function to play with that data(while loops)?
Re: Recursive Code Challenge
When I said efficiency, I was refering to the fact that recursive calls are reputed inefficient in LabVIEW. I guess It is less efficient to instanciate the VI space than to pre/reallocate an array for next data level. Often it is not possible to figure how is big enough without first digging in the recursion tree. It seems to me that recursion is needed when you you didn't think you would have needed it in the first place!!! (design phase) It is the nature of the task that requires recursion, not the designer to decide! But the programmer can implement it with recursive calls or while loops. Jean-Pierre Drolet www.avensys.ca - Message d'origine - De : Dominic Lavoie [EMAIL PROTECTED] À : Jean-Pierre Drolet [EMAIL PROTECTED]; Info-LabVIEW [EMAIL PROTECTED] Envoyé : 4 juin, 2004 10:13 Objet : RE: Recursive Code Challenge Couldn't you just allocate a big enough stack to begin with, or allocate chunks of it as you go on(initialize and resize array) and get an efficient behavior? It seems to me that recursion is needed when you you didn't think you would have needed it in the first place!!!(design phase)
Re: ActiveX Remote access
Look here: http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/38787589f325412186256de100671a8e?OpenDocument Jean-Pierre Drolet www.avensys.ca - Message d'origine - De : Norman Kirchner [EMAIL PROTECTED] À : Info-LabVIEW [EMAIL PROTECTED] Envoyé : 4 juin, 2004 14:05 Objet : ActiveX Remote access Is it possible to open an automation reference to an activeX control in a VI running on another computer on the local network, and how? On the Automation Open function there is a machine name option which allows me to reference the other computer. I've selected the intended class that I will be accesing, but I need that next step/configuration on the remote machine that will complete the circuit. And they're off Norman J. Kirchner Jr. Automation Software Engineer Engineering Specialists, Inc. (262)783-8000 (262)783-8001 Fax
Re: ActiveX Remote access
Sorry, it is there: http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B123AE0CBA64111EE034080020E74861p_node=DZ52051p_source=External Jean-Pierre Drolet www.avensys.ca - Message d'origine - De : Norman Kirchner [EMAIL PROTECTED] À : Info-LabVIEW [EMAIL PROTECTED] Envoyé : 4 juin, 2004 14:05 Objet : ActiveX Remote access Is it possible to open an automation reference to an activeX control in a VI running on another computer on the local network, and how? On the Automation Open function there is a machine name option which allows me to reference the other computer. I've selected the intended class that I will be accesing, but I need that next step/configuration on the remote machine that will complete the circuit. And they're off Norman J. Kirchner Jr. Automation Software Engineer Engineering Specialists, Inc. (262)783-8000 (262)783-8001 Fax
Re: Comment sur chaque pts d'un graphe superposer un curseur
Utilise la propri=E9t=E9 Cursor List (ou l'=E9quivalent fran=E7ais). C'es= t un array de propri=E9t=E9s de tous les curseurs. Le nombre d'=E9l=E9ments d= ans l'array d=E9termine le nombre de curseurs que tu auras.
Re: How would you recommend that I schedule a file-creation...
To avoid polling you could calculate (in a separate loop) the amount of time left before the next save and then feed this time to the timeout of a wait notification node. When the notification times out, write file. Other processes can control/abort this loop sending notifications to the loop e.g. when the wait notification node returns, you check for notification data or a timeout.
Re: [W] user specific LabVIEW ini file
Jason, Like others have said, have a shortcut with the -pref switch on the command line. I use to have one shorcut and one labview.ini file for each project. That has the advantage to set the default directory to the project directory and to have a different Recently Opened Files lists. For those using builtin SCC, setting different default directories for projects allows to use different SCC repositories and settings. Jean-Pierre Drolet Avensys www.avensys.ca
Re: Turning off right click on table in 6.1
There is a VI setting to disable right clicks when the panel is running in VI PropertiesWindow AppearanceCustomizeAllow Run-Time shortcut menus. This will disable RCmenus for all the FP. For an indicator, you can disable it to prevent the RC menu to appear. However, the user won't be able to select and copy data from the content.
Re: How to reopen a same vi ?
Qu=E9b=E9cois. Quand le template VIT (avec l'extension VIT, pas une instance Template N.vi)est en m=E9moire et que tu ouvres une r=E9f=E9rence au template, tu ne cr=E9es pas une nouvelle instance. Tu ouvres simplement une nouvelle r=E9f=E9rence au template. C'est pourquoi tu ne le vois s'ouvrir qu'une seule fois. Une fois que ton VI appelant a ouvert une r=E9f=E9rence, ouvert la face avant et lanc=E9 le VIT, il peut fermer la r=E9f=E9rence; le VIT va continuer de tourner. Il ne faut pas que le VIT soit en m=E9moire pour cr=E9er diff=E9rentes instances. C'est =E0 dire que la face avant est ferm=E9e et que toutes les r=E9f=E9rences sont ferm=E9es. Lorsque tu ouvres une r=E9f=E9rence alors que le template n'est pas en m=E9moire, alors une nouvelle instance et une nouvelle face avant est cr=E9=E9e =E0 chaque r=E9f=E9rence que tu ouvres. Donc si tu viens d'=E9diter ton template, tu fermes la face avant avant de lancer ton VI Top Level. Le VIT va aussi rester en m=E9moire lorsqu'il est copi=E9 sur le clipboard ou sur le diagramme d'un VI appelant.
Re: can I see Labview discussion Forums in Outlook Express
Or a href=news:\\newsgroups.ni.com\comp.lang.labview;Click Here/a.
Re: can I see Labview discussion Forums in Outlook Express
Copy the link in your internet browser...
Re: How to reopen a same vi ?
It is just that the template VI must not be in memory when you want to instanciate it. Make sure that the template is closed before running a new instance.
Re: cluster names and data types
Joolz, In LV7 (don't know about LV6.1) get the bValue/b property and feed it to the VI located at a href=c:\Program Files\National Instruments\LabVIEW 7.0\vi.lib\utility\GetType.llb\vi.lib\utility\GetType.llb\Get Type of Variant.vi/a. The output is an enum with the data type. If the VI is not in LV6.1 then it is time for yet another shameless plug for the LabVIEW Data Tools in the OpenG Toolkit at a href=http://openg.org/tiki/tiki-index.php?page=OpenG+Toolkit;OpenG.org/a and use bGet TDEnum from Data/b.
Re: Is there something to reset all indicators when the VI is open?
In the VI Properties, execution options, there is a checkbox bClear indicator when called/b. That clears graph when the VI is called or when a top level VI is run. If your subVI is set to open FP when called, that will do what you want. If you open the panel using VI Server, you may also use the VI method bReinitialize All To Default/b.
Re: Can I call a labview VI from a batch file?
Scott, Be sure to enclose the path to LabVIEW and started VI within double quotes, e.g. C:\Program Files\National Instruments\LabVIEW 6.1\labview.exe c:\path\to\Vi.vi To start LabVIEW without the batch file waiting until it's done, use the start command: start c:\program files\national instruments\labview 6.1\labview.exe c:\path\to\Vi.vi The first argument is for the window title and is left as empty double quotes. It works on W2K and it should be the same for Win98. Jean-Pierre Drolet www.avensys.ca - Original Message - From: Scott Serlin [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, May 17, 2004 5:33 PM Subject: Can I call a labview VI from a batch file? With much frustration, I cannot seem to get my labview vi to run from a batch file. Everything appears ok in terms of the directory and filename but I keep getting a bad filename error message. Anyone have any ideas around this? I also tried using the call command with no such luck. Windows 98 is the OS run lv 6.1.
Re: Type issues in LV
To some extent, you can compare two variants using bEqual?/b comparison nodes. There are some issues as 0.0(DBL) will be different from 0(U32) and NaN(DBL) will be equal to NaN(DBL) (IEEE spec requires that (NaN == NaN) should return False). Take a look at LabVIEW Data Tools in the OpenG Toolkit at http://openg.org . There are tons of VIs to manipulate variant data.
Re: how can I do cluster with both indicators and controls
Je crois que tu as simplement besoin d'un peu de temps pour t'habituer =E0 la fa=E7on de programmer avec LabVIEW. Il est normal de s=E9parer les commandes et les indicateurs. Sur la face avant du VI, rien ne t'emp=EAche de regrouper visuellement les donn=E9es. Habituellement, quand je dois faire une interface usager, je rend invisibles les contours des clusters et je regroupe ensemble les commandes/indicateurs dans un cadre(d=E9coration). Il n'est m=EAme pas n=E9cessaire d'utiliser des clusters car tu peux faire un bundle dans le diagramme pour regrouper les donn=E9es (et l'inverse). Bref il arrive souvent que la structure des donn=E9es telle que pr=E9sent=E9e =E0 l'usager soit diff=E9rente que celle que tu utilise sur le diagramme. Si tu veux, publie ton VI dans ce forum et on pourra regarder quelle est la meilleure fa=E7on de g=E9rer ton interface.
Queues and built application
Hi, I have a LV7 built application that works well on many computers here but, of course, doesn't on the customer's computer. As far as I can tell, the queue (LV6 VIs) of the UI state machine doesn't work as none of the events queued are triggered while event structure works when event is managed immediately instead of being queued. The culprit computer is a Compaq Evo N600s running Windows 2000. Has anybody encountered similar problem? (before I spent the rest of the week to nail it myself...) Jean-Pierre Drolet Avensys
Localized units
Hi Can someone tell me if LabVIEW localizes units abreviations such as ft (foot) and d (day)? In French LabVIEW will they be displayed as pi (pied) and j (jour)? Thanks Jean-Pierre Drolet Avensys
Re: Compiler error: Code could not be generated
The VI compiles in LabVIEW 6.0.2. You are using version 6.0. Since the problem seems fixed, you should upgrade to 6.0.2.
Re: How can I obtain a reference to a global variable?
Hint: an excellent answer provided with a working example certainly worths a ! (it's four stars rating... not censored =A6=AC) It may not be the solution you expected but it is not the poster's fault after all...
Re: How do I define symbolic constants?
With LabVIEW 7 you can use a ring constant with non sequencial value. They take less diagram space than a global and the same ring can hold several related values. The best is to save the ring as a strict control typedef so that all occurences of the ring will change when you modify the typedef. If you have symbolic constants defined in terms of each other, e.g.b #define array_len 100 #define array_size array_len*sizeof(data_type) /bthen you'll have to use VIs to compute the values. Use the VIs directly or use them to initialize globals.
Re: Alternative info-LabVIEW list
I would like to see Info-LabVIEW on a news (NNTP) server. I sure hope this doesn't happen... I have tried and tried to get our IT guys to open up NNTP for me. They simply won't do it... I am sure there are many others in the same situation Scott, Would it be possible for the mailing list to be mirrored on a news server? This way one could browse messages by threads with one's favorite news client. I remember having read somewhere that some company (is it NI?) does that internally to distribute the Info-LabVIEW mailinig list. I don't mean a public USENET newsgroup but maybe a private news server accessible only to the list subscribers. Jean-Pierre Drolet Avensys
Re: serial TX completion
It is not something I've tested actually but if you use bVISA Write/b node, the help says: Right-click the node and select bDo I/O Synchronously/b from the shortcut menu to write data synchronously. The operation returns only when the transfer terminates. Take also a look at bVISA Flush I/O Buffer/b. With a mask 32, it is supposed to return after the TX buffer is emptied.
Re: Communicating Between Built LV App.s
It will work fine but still requires TCP for VI Server operation...
Re: PushOK CVS proxy
Craig, There is a tool called LVDiff written by Ian Dees at SourceForge that allows to compare VIs from TortoiseCVS. You just have to enter the tool path in TCVS settings to have it lauch LabVIEW VI comparison tool with the two revisions to compare automatically. Jean-Pierre Drolet Avensys - Original Message - From: Craig Graham [EMAIL PROTECTED] To: Jim Kring [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Monday, February 23, 2004 4:12 AM Subject: Re: PushOK CVS proxy Yeah, I use Tortoise, but doing it inside Labview would give me the advantage of being able to view the changes between two versions, if I understand right. I guess I could manually check out two versions to two different directories and do a compare manually, but that's more hassle. Less hassle than screwing the registry though, since there are many hits on the term vss and some don't look like I should play.
Re: Text Selection and Font Color Bug?
The problem is that you rewrite the whole text on the indicator and LabVIEW has no clue that you just append new text and want to keep current colors. To fix this you have to keep a table of position/attributes and recolor the string each time the string is rewritten.
Re: Associate a type of file with a LV7 app
Ha! my pet topic. Alas the solutions proposed previously won't work when LabVIEW is already running... The trick is to build a small executable and then associate the file extension to it. This small application, reads the file path from the command line and then launches LabVIEW (if necessary) and runs the appropriate VI using the VI Server. That requires the TCP VI Server be enbled on LabVIEW. The launching applications then quits and is ready for the next call. Jean-Pierre Drolet Avensys
[W] Image acquisition
Hello all. I'm not familiar with image acquisition and I have to communicate with a CCD camera, Photometrics CE 300, using its driver PVCAM. The camera acquires a spectrum and the only processing required is to sum horizontal or vertical lines into bins. I have LabVIEW 7 Pro and I would like to know if someone here can tell me what else is required to get this job done. Thanks Jean-Pierre Drolet Avensys.
Re: [W] Image acquisition
Hamid, I have to upgrade an old Turbo Pascal (DOS) application to LabVIEW with the currently perfectly working hardware. The camera is cooled with liquid N2. I've already began to write an interface to their PVCAM DLL and it shouldn't required more than a dozen of CLNs to get what I need. Thanks to those who replied. Jean-Pierre Drolet Avensys - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: Info-LabVIEW Sent: Wednesday, February 04, 2004 3:54 PM Subject: Re: [W] Image acquisition Hi Jean-Pierre; I had to look for this particular camera (photometrics 300). I did not spend much time but it seems to me that the camera is made by Roperscientific and they also provide the frame grabber (PCI bus). By the sound of it, I guess the camera is RS170 and most probably has some special features which makes is so special! (I guess it communicates with the card). Now, I don't know what exactly you want to do? I guessed you want to write a particular program in LV. If you want to have the functionality of PVCAM (I think it is Roper's software) then you will need more information regarding their DDL's and most probably their SDK. If you can get hold of the pointer to the pixel values in the memory, (assuming you would know the image format) then the rest of the job is a piece of cake! But getting hold of that pointer may not be an easy job. What would I do? I would buy a frame grabber from NI and a compatible camera according to my application and then IMAQ 7 and viola! If you need further help please contact me Regards + Dr. Hamid R. Yazdi Federal Mogul Manufacturing technology 3935 Research park drive Ann Arbor, MI 48108 Tel: 734 222 4108
Re: Unable to install when 32GB free space available
Not absolutely crazy, I think. I vaguely remember having had this problem once, and maybe not with LabVIEW. However, I think the older installer receives the free disk size modulo 2GB (I32)or 4GB (U32) so you may have to create a file large enough just to get under 32GB or 30GB free space boundary. If I remember correctly, I solved this by duplicating the Windows or other large directory. Not easy to explain to a customer...Good luck!
Re: Programatically Changing Cluster Size
Eric, It is not possible yet for the Array to Cluster node to adapt to the size of the output it is wired to. However in the OpenG LabVIEW Data Tools, there is a VI Array to VCluster that converts an array into a variant cluster of the same size of the array. Wire your array to the input of that VI and wire the variant output to the Variant to G Data primitive and then to your cluster. When Variant to G Data is not wired directly to a typed input (such as a tunnel to a structure) the wire may be broken. Connect a local variable of the cluster to the type input of Variant to Data node. Basically, Array to VCluster takes the flattened data of the array and formats it in cluster flattened data and dynamically generates the type descriptor of a cluster having the same number/type of elements as the array. Flat Data and type descriptor are then converted into a variant using the primitive Flattened string to Variant. You could probably make a subVI out of this piece of code and, using a typedef for the cluster, have code that doesn't break when the cluster size is changed. Jean-Pierre Drolet Avensys
