alukindo

Hi: Regarding your first question, I am not sure what you mean by 'database lock' and how it avoids re-connecting. Please explain that further. Non Elastic Behavior of Databases --------------------------------- Otherwise, databases such as MS Access and MS SQL Server have a behavior of expanding in size when data is added and will not reduce in size when data is deleted. What actually happens is that the database continues to occupy 'un-used' space. This behavior is also described as non elastic expansion behavior of databases. Reclaiming Un-used Space --------------------------- However, you can still intervene to re-claim the unused space in two ways: (1) Manually, by using a database management tool; (2) Programmatically, by writing a special SQL command to shrink the data file. To shrink the database manually see illustrations below. To shrink an MS SQL Server database programmatically, you can use the following Command: DBCC SHRINKDATABASE (0,0). You must log on to the target database before launching this command. Anthony L.

Hello: When printing a LabVIEW front panel with an embedded picture control, the picture control's image quality is seriously reduced and appears fuzzy. In my case I am using the picture control as a report builder because it allows aligning text vertically. . . . . Any thoughts on how to get the picture control to output clean/sharp PDF or printed images of itself? Attached is a sample of the report. The header is a picture control while the rest are LabVIEW controls Thanks Anthony

Hi Crelf: Thanks for your explanation. I figured that we are working on different philosophies where you define software development as an 'engineering process' while I define it as a 'craft' aided by certain rules. Thus we will continue to have somewhat differing views on this subject which is OK. BTW: The question on 'newer projects and clientele profile' was a general one intended to differentiate project types that you do now versus the older (smaller) projects that you noted you did in the past. In no way did I intend to divulge your business relationships or client-base. My apologies if it seemed that I was trying to spy on anything. In any case, when I visited the VI Eng web site I got direct answers to that question. Regards Anthony L.

Hi Crelf: You are right that how can you deliver a project against requirements and yet find that it does not meet those requirements. Usually what I find is that the written-down requirement statements may be met but what lacks is useability or lack of small user-features that look insignifucant but prove to be critical in getting the larger task accomplished. The commissioning test will even pass with good reviews. But after three to six months of use, user complaints creep in based on scenarios of use that make the application look cumbersome or even a show stopper. QUOTE (crelf @ Jul 6 2008, 09:34 AM) Crelf, it is interesting that you mention doing those types of projects 'many years ago'. So could it be that your latest projects are larger projects where you have a long term working relationship with your clients? I am interested and would appreciate clarification on the nature of the newer projects and your general client profile? E.g: Are the customers aware of the software development process? Do they do many software projects? etc, etc. The interesting part is how did you transition and stay focused on these other projects? Thanks Anthony

Hi Paul: Just to clarify, here I am talking about a rather comprehensive project. Not a simple setup application that controls say a motor or heater. Otherwise, I understand that the general requirements statement in my posting is subject to varied comments. However, perhaps the broader question is why do companies buy-out other software companies to get their products while they have a large team of internal developers who can gather requirements and supposedly build the same piece of software? For example why did Oracle buy Peoplesoft and Siebel ---Buying market share could be a big reason but Oracle was in the same field earlier than these other companies. Infact Siebel was started by a former sales employee of Oracle (Tom Siebel) who turned into a developer. After ~10 years doing software development, with 5 of those years doing consulting projects for other clients, I've come to a point where I feel that to build a really successful comprehensive product where a majority of stake holder users readily accept and find indispensable, one needs to be close to the field of application and understand the users very intimately. One needs focus, specialization, and numerous field trials over an extended period of time. Transferring requirements from paper to software say in six months rarely results in a really good comprehensive product. As I write this I continue to do what I call 'one-off projects' and I try to get requirements fleshed out in detail. However, the time alloted to complete the project allows a so-and-so piece of work to be delivered and there is always a shortlisting of requirments to balance-out the cost. . . . But thanks for looking out for me. I think I understand the comments you posted. Anthony L.

Hi: I am finding that its is hard to develop really useful applications when doing one-off projects where a customer writes a one or two page requirements document and wants an application to meet those requirements. Hence, my focus these days is doing specific applications targeted to a given field or clientele. Currently these fields are Geotechnical Materials Testing Informatyion System (MTIS) also known as LIMS (Laboratory Information Systems) and Measurement While Drilling Applications & Logging While Drilling Applications (MWD/LWD). A link of GUI for these is available here. . . . if anyone is in the same field for these applications we can communicate further. Thanks Anthony L.

Thang: I use quite a bit of ActiveX. I am curious as to what you are doing inside the initialize ActiveX subVI. E.g: Do you start a new instance of ActiveX ref as you initialize in the loop? Also, is your ActiveX an *.OCX or *.Dll file? Theses behave very differently. I think that you should try and re-solve the hanging rather than trying to find a way to bail-out if the initialize step hangs. May be able to help further if you show the inside of the initialize ActiveX SubVI. Anthony.

Hi: If you are using a *.DLL rather than an *.OCX ActiveX component you must initialize your reference using the VI code portion below. However, if you did that already then this should not be what is causing your problem Anthony

Hello: Thanks for the activity on this question. My VI has one Active X control window so I may be able to use this technique. I need to test to see if the handle will render the 3-D control on the document. Will soon provide feed-back. Anthony

Hello: Component Works control, namely the 3-D plot control, is infact an ActiveX control. Yet, its LabVIEW property node does not expose an hWnd property. Does anyone know why? I need this to use a third party reporting tool to render the image of the object on a report page. . . . I know that this can be done using LabVIEW's getImage method but I want to use the hWnd approach because it gives cleaner report print-outs. Thanks Anthony

Dan: The other question is whether the driver file is delivered as an ActiveX *.OCX file or and ActiveX *.dll file? These behave and need to be treated quite differently. Anthony

Dan: How are you capturing events for the ActiveX control? I am assuming that you may need to capture mouse events and others. ActiveX controls can be registered to capture their native events via LabVIEW ActiveX Events call back function node. Some times this method works better than capturing the events using LabVIEW polling or by using LabVIEW's own event structure. Attached is an Example node where ActiveX native events are captured via a LabVIEW call-back function node. This is for an ActiveX grid that I use with LabVIEW. Anthony

Hello: I need to write a LabVIEW installer that will reboot and resume the install process by executing a known exe. Is there a way to do this in the LabVIEW installer or can one write a batch file or script that will invoke reboot and then launch the target exe? I was thinking of getting WISE installer or Install Shield to help do this. But then this reboot and re-run feature is the only missing thing in my current installer. Thanks Anthony

Hi Tomi: This is a great example of LVOOP. Thanks for contributing this. I was looking for documentation on LVOOP and you have just made a great one available! Regards Anthony

Vladimir: If you want these notifiers to behave as two separate ones then you have to initialize them with different 'assigned names'. Else, you really have just one and the same notifier. There is an optional terminal on the create (obtain) notifier VI which you can use to name your notifier reference. Otherwise, the default name is an empty string. This same rule apples to Queue References, Semaphores etc. Actually I think it is good practice to always name your Notifiers, Queue, or Semaphore references even if you are using just one of them. Anthony

QUOTE (jlokanis @ Mar 14 2008, 05:26 PM) John: I think that ADO exposes a high level and simplified API with the requirement of using any other COM-compatible lower level driver. This means that at least one other lower level driver layer must be there for ADO to access a data source. To meet this requirement ADO comes bundled inside MDAC (Microsoft Data Access Components) which includes lower level drivers for ODBC, OLEDB, as well as ODBC for OLEDB . However, the SQL Native Client driver that was released with SQL Server 2005 is not an OLE DB type driver and is 'native to SQL Server'. This is why other than requiring ADO you must also have the SQL Native Client driver. This SQL Native client has never been part of any version of MDAC. Note also that the example connection strings that I included in the previous post refer to Driver={SQL Native Client} At some point I figured that ADO.NET technology is mostly suited to web access where connections need to be closed from the data source and have the data reader component work off-line. There is also database schema that ADO.NET exposes. But for simple data access chores, ADO does a very good job. . . . just my two cents worth. Anthony

Hello jlokanis: I continue to use ActiveX Data Objects (ADO) to access SQL Server databases ---but also use the latest SQL Native Client drivers for enhanced performance. I have attached a single VI that works as a functional global that I use to connect, read, and write to SQL Server 2000/2005 databases. There is an example with notes that can help you to implement this method. I have included web links to driver files that you may need. Keep in mind though that the fastest read/write operations that can be achieved with databases is about 300 round-trip calls per second. You can, however, use methods such as 'Bulk Copy' or 'Bulk Insert' to export/import ~300,000 rows of data per second or better. Anthony

Sara: This means that one of your SQL queries which contains an INSERT statement has a code or syntax error. Post the query and someone may be able to help you. Anthony

Your code shows that your column names include spaces, this makes SQL code prone to errors. For table names, you should use underscores symbol ( _ ) instead of spaces and then try again. This assumes that you were able to succesfully connect to your ACCESS Database Anthony

... I have LabVIEW 8.5 in my in-tray, and after installation, I determined that this newer version prints the Front Panel OK. The one that had problems was LabVIEW 8.2.1. I had yet to use LabVIEW 8.5 after the driver conflict alert. Anthony

LAVA Members: Can someone provide input as to why this VI prints a 'BLANK' Front Panel? or are others possibly getting different print results? The VI: 'Easy Print Panel' under the [report generation] VI pallete is able to print this FP but the output is quite blurry. . . . . As far as I can tell, the broken print feature started appearing as of LabVIEW 8.0. :headbang: Anthony

Happy New Year 2008! After a PXI RT-controller was repaired and had software updated, the system exhibited floating behavior for all strain gage channels via an SCXI-1520 and SCXI-1314 connector block. The system lives in a PXI/SCXI combo chassis i.e. PXI-1011 and was put together in 2003 using Trad DAQ. The system worked fine since 2003 until recently. I have tried to revert the controller back to old software used in 2003 i.e: LabVIEW RT 7.0 and Trad DAQ 3.0.1 but the controller will not even let me install the 7.0.0 RT software after I reformatted it. The controller will however, happilly accept higher software versions. I have two host PCs one with legacy software (LV and LV RT 7.0) and one with newer software (LV and LV RT 8.2/8.5). Extensive troubleshooting was done to isolate faulty hardware component but to no avail. This behavior was later duplicated on a second system and this channel float behavior continues to exhibit itself even when using a regular battery (full bridge, no excitation) ****By floating I mean that the measured channel drifts by small voltage amounts until it becomes outside of the configured range. The system works OK in DAQMx and will also work OK in Traditional DAQ ---when using a controller with Windows OS. The problem only happens when operating under remote connection under LV RT OS. Any pointers to the possible cause of this behavior? Thanks Anthony

Hi: As of LabVIEW 8.0, LabVIEW will print graphs with the plot area empty! All grid lines, controls, etc will show up OK, but the all important graph will be empty! In some cases LabVIEW prints empty pages altogether. NI application engineers acknowledge that this is a known bug but it is yet to be fixed as of LabVIEW 8.5. The work-around I am doing now is to capture a *.png image of the original front panel and import that into a picture control and print the FP panel of the VI with that picture control. However, the print quality degrades due to this image handover process. Can NI please elevate the priority for this problem for fixing in the next release? Anthony L.

Hi Neville: The terminal blocks on the SCXI 1520 modules are the SCXI-1314. Excuse my asking: How do I exactly identify or locate the 'interconnect board' or 'grounding plane' that connects the above terminal block, via the chassis, to the DAQ card and how do I inspect for signs of it being fried? Thanks Anthony

Neville: Thanks for the advice. The unit is getting shipped back from a remote site in the field. So I will examine the grounding at that time. I did check one channel on each of the five SCXI 1520 boards, one-by-one, with a steady voltage source and each and every one of those five boards gave me a wrong floating reading. My LabVIEW code gives me NaN and the Trad DAQ clock config VI throws the error: 10685 = 'The scan rate exceeds the board's recommended maximum scan rate' which is of course not true because this is the same scan rate that I safely used before. When use that same scan rate in MAX I get a fault error as well. Somehow I find it unlikely that all five SCXI 1520 boards are faulty but this could also be the case. BTW: I am looking to get a spare SCXI-chassis and test the SCXI 1520 boards. Anthony