Rolf Kalbermatter

I can only confirm the upgrade pains. When it was BridgeVIEW it was a predominantly LabVIEW based system with some external Logos (Lookout) components added in. Each version removed quite a bit of the LabVIEW based components and replaced them with the newest hot from the press NI technology. These replacements were supposed to be seamless, but in practice always caused various pains. And even once replaced technologies got sometimes replaced with yet another even newer technology. All in all I can't say that I can still work with the DSC toolkit anymore as just about anything is very different than it was at one time. Also I do have developed over time my own entirely LabVIEW based data logging and monitoring system, that has many of the features of the original BridgeVIEW based system and works perfectly fine, so my need for DSC has more or less completely diminished. Additional bonus of this system is that it also ports quite nicely to RT targets like CRIO and Compact Fieldpoint. That required some initial work to make it work fine on those resource constrained systems but by now I can move an application based on that framework almost seamlessly between desktop and those RT targets. And multiple applications can communicate with each other their tag database so really distributed systems is just some extra initial configuration effort away.

Not really much NI can do about it. This is not a standard socket property at all and Windows socket implementations don't even support to set it through the API. So even if NI ever decides to add a property interface to network refnums, it's not possible to change this setting from the program in any way. And the 200ms acknowledgment is a standard TCP/IP socket feature, that Microsoft implemented in Windows 2000 to conform to the standard. So the really faulty party here is the PLC that resends already after 50 ms if you want to call it a fault. Realistically it's just a workaround to guarantee that any packet is acknowledged after not more than 50ms :-) Enabling this registry setting in Windows is the only way to change this setting, and you don't want LabVIEW to change this behind your back in the registry ever! Especially since it enables this feature for any connection on that interface, which can be a real burden on network traffic if normal internet traffic also happens to go through this interface.

Yes! An invisible wiring error? It's about 99.99% of the cases for me when I see such strange behavior. The wire looks as if it is coming from the tunnel but in reality comes from some other place, that resets the reference. Or there is a tunnel that uses default data if not wired, and another one on top that caries your reference from that case but goes nowhere. That is one reason that I really think twice before enabling the "Use default Data" on any tunnel.

Well there is a #pragma pack(1) so it sure will work. And more importantly, this structure has no alignment issue since a float is a 4 byte entity, so together with the int it aligns the double on an 8 byte boundary, no matter what packing definition is used. Change the float to a double (and make the according change in the VI too!!!!) and the #pragma gets important again (or he also changed the default alignment in the project settings!).

If it is Visual C+ it for sure uses 8 byte default alignment. So wrap the declaration of the struct between #pragma pack(1) typedef struct { .......... } Structname; #pragma pack() [/CODE] It's always a good idea to reset any alignment setting back, as otherwise you get a big mess with the order of includes changing the behavior.

I think so. Leave it on sourceforge for whoever wants to look at its implementation and do his or her own stuff with it. But it probably shouldn't be an official OpenG package anymore. I started it for a quick and dirty test once, and after it got a personal thing between me and Windows, to try to force it into submission . Once that point was proven it lost its appeal for me. I learned quite a bit about Windows device driver programming with it, but mostly stuff I didn't want to really know.

Most likely you don't want to call the Constructor Node at all after the first initial call from your Top Level routine. Proper solution would be to separate the Construction of the object from any other initialization that you might want to do from your plugin. A quick fix would be to wrap the Constructor Node into a case structure that is selected by the Not A Number/Refnum primitive, This will create the refnum anyhow the first time around (and even if it got somehow invalid in the meantime, which it shouldn't anymore).

I personally find 2009 a rather steep step to go to. I still have projects that are maintained in 7.1.1 and I don't like to go through hoops to backconvert the code after each modification. I can look into the directory layout you mention. Can you point me to a document that describes the specifics and the exact problems this is supposed to solve? PortIO is as far as I'm concerned EOL. I don't plan to do any maintenance on that. It solves a problem that should be not even considered as a solution in modern OSes, and uses technology that is very unportable to other LabVIEW platforms, including 64 Bit Windows.

The recommended way to do what you want to do, without even having to issue VI server calls to open and size the window is to simply select under Windows Appearance in the VI settings the Dialog option. This will change various specific settings, such as Show FP when called and close afterward, modal state, disable scroll bars and a few other things. Especially under Windows, some of these properties are exclusive, meaning that if you enable or disable one of them you also disable or enable something else automatically, and LabVIEW can't even do anything about it. You still can execute code to size and place the dialog if you need to, but should try to minimize the number of programmatic changes to window style modifications as much as possible, as they can unset settings you made in the configuration implicitly.

This is a library implemented in C, that claims to implement the ONC/RPC protocol. It's old but fully based on the original Sun specs. This is a C# implementation and this and this are in Java.

You could save the cmd intermediate process creation altogether by directly piping into the (Mercurial) command line tool. And if you use the OpenG Pipe functions you could potentially even use the same single mercurial command line instance to issue many commands after each other through a pipe to the stdin and receive any response through another pipe from stdout. And your hunch that process creation is quite an expensive task under Windows is quite right. And doing this through CMD really doubles that. But unless you need to also access Windows shell features, such as its build in commands, or locating an unqualified executable name in one of the PATH directories, it should be usually not a problem to directly instantiate the target command line app, by simply issuing its fully qualified exe name as first parameter, leaving out the cmd \c step completely.

Not really. If you compare the typestring of an ActiveX refnum with another typestring of a ActiveX refnum it only is equal if both UIDs are the same. The class GUID is basically the whole class and the interface GUID is the actual interface implementation. If only the class GUID is the same, then it is not the same refnum type, but a different one (with usually different properties and methods).

Thanks for pointing this out. And no I haven't run the ZLIB library on every possible target that is out there. For several good reasons: 1) I don't have all that hardware available. 2) I do have a normal daytime job to earn my living 3) LVZLIB already is targeted at Windows 32 Bit, MacOS Classic, MacOS X 32 Bit (with some issues related to long path names), Linux, Pharlap ETS, and VxWorks and I'm working on Windows 64 Bit support too. Testing the library myself on all of these systems with many different scenarios is simply not an option. What I did in case of the RT targets, was simply to assume that the ETS Pharlap system should work with the same code as the Windows system. In the case of the VxWorks system I simply compiled the according .out file and asked people to test it, which it of course didn't to start with. Thanks to a very helpful engineer at NI who had access to the (rather expensive) integrated development system for VxWorks we could debug the issues, which required actually some significant changes to the entire source code framework to make it work for VxWorks. As to the path handling: Can you positively confirm that your change will work without issues on all the aformentioned targets? If someone can confirm this to me, it would be fairly easy to make the necessary changes to the library, possibly at a place that is actually less performance intensive, such as in the actual shared library code itself. Specifically the change to the path separator should be handled in "ZLIB Common Path to Specific Path.vi" instead. It also takes care of stripping the path from any trailing seperator. So the real fix is to simply use this VI. The VI in the SVN repository does this already and I changed that in April of this year, but for some reasons, your library doesn't seem to use that VI. I'll check what the OpenG library contains and if there is indeed some problem with having the latest source code in the package. EDIT: Ok I checked. 4.0.0-2 seems to be based on the old 2.5.1 source code and doesn't contain the fix to treat the Pharlap platform as Windows platform in the "ZLIB Common Path to Specific Path.vi". But the orginal code contains definitely the "ZLIB Common Path to Specific Path.vi" in the "ZLIB Extract All Files To Dir.vi" and the only thing needed to make it work for Pharlap platforms is to add the Pharlap enumeration to the case structure inside "ZLIB Common Path to Specific Path.vi" that handles Windows 3.1 and Windows 95/NT enumeration already. No need to handle directories and files differently as the LabVIEW Build Path primitive is smart enough to work for both correctly.

The code as posted in the diagram won't work at all. You can not emulate an embedded fixed size array in a cluster with a LabVIEW variable sized array at all. Instead you have to use a cluster which contains the same amount of elements of the same datatype, to match the fixed size array. So a GUID is really a cluster of type { uint32,uint16,uint16, {uint8,uint8,uint8,uint8,uint8,uint8,uint8,uint8}}

This is a smart implementation but I personally would feel a little concerned about creating a potentially large XML string to get such an information. The solution from the original poster had one big problem that it only really checked for the refnum to be ANY ActiveX refnum. It should have gone further to not only compare two elements from the typestring but in fact 23 (possibly even 27 but I'm not sure those additional 4 words provide any meaningful information). Basically the ActiveX specific typestring description contains a 0x3110, 0x0, 0x4, <16 bytes for the ActiveX Class GUID>, 0x0, 0x1, <16 bytes for the Interface GUID>, and then some other stuff (usually 0x0, 0x1, 0x0, 0x0). It's quite possible that the constant numbers could change with different ActiveX refnums, but my own testing seemed to indicate that they stay the same for several different ActiveX refnums, and quite likely are really the same for the same ActiveX type. To be really right the higher significant byte of the 2nd value of the full typestring should be masked out, as it contains LabVIEW private flags about the control the wire comes from.

That's not scripting but an intentional feature when properties were introduced. There isn't much else you can do on a running VI if it's not done in a control as data change.

I'm not sure how this stuff is implemented, but could it be simply so that the according license file is added as a resource to the executable? In that case it should be possible to hack the resulting LabVIEW executable to include this resource in its resource directory. Finding out the resource type and ID would then be the only challenge left to do.

If you happen to include the VISA runtime installer into the application installer you have to make sure to also add the NI-Measurement & Automation Explorer in the Additional Installs settings. DAQmx allows to select several different Install Types with most of them including MAX. VISA runtime only contains the runtime but at least in newer LabVIEW versions you can select MAX as an extra component.

There is the hardware limitation for sure. A device oriented USB connector should be a USB-B connector not an USB-A connector. I haven't seen a single computer hardware with USB-B connectors so far. Electrically there is not really any difference but the software stack is again different. I'm pretty sure that it would be possible to write a USB device stack for XP but that involves going into kernel mode. Maybe, just maybe, it could be possible to emulate the device stack in user space on top of a library like libUSB or the native Windows USB device driver API, but that only would alleviate the device driver debugging issue, not the whole trouble of implementing a valid USB device stack.

Your reasoning mixes again two rather unrelated things. That of hacking password protected VIs and that of hacking the LabVIEW license. For both you do need to to dig into disassembly if you don't want to go the brute force attack through GPU path, but they are not directly related to each other. I haven't looked at the details for some time, but from what I saw earlier the license generators you could find were always tied to very specific LabVIEW versions. I think the license technic hasn't changed since about LabVIEW 7.1 so it might be possible to generate a key generator that works across versions, but I don't know. I'm not sure if there is a single person who knows how to open password protected VIs in all possible LabVIEW versions, but I'm certain there exist people who can open password protected VIs in certain versions of LabVIEW. And they don't work for NI, as NI has of course the ability to work on the source code directly to circumvent such protection. This means, don't trust your super secret 5 million dollar idea to password secured VIs but also don't expect or require NI to provide such a possibility. It is technically simply not feasable to create a really secure protection without at the same time throwing away the advantage of not having to remove the diagram and making a VI only readable in the specific version and platform it was created in.

It's a violation of the license agreement indeed, though I doubt a hacker feels much bothered by that . The other issue is that you need to do disassemble and that is not trivial. It is made extra hard by the sheer size of the LabVIEW executable nowadays. Even a very good disassembler takes a few hours to get a raw disassembly for such a huge executable. And then you can sift through million lines of assembly code to find the places where the MD5 hash is checked. And looking at assembly for even a 100k DLL is already a rather boring job. The fact that every half year a new executable is released makes the task even more hopeless. So while I'm sure there exist hackers who have hacked one or two versions of LabVIEW to that extend they really won't keep on doing that over the years as the gain of this is minimal. There is very little you can really see from most password protected VIs. Bragging rights don't apply because if someone does that, he might get a cease and desist letter or even worse, signed by the legal department of NI. I have at some point looked at the possibility to simply modify the VI and that seemed just as hopeless. Especially with VI libraries involved, which contain also a password whose hash is even out in the clear in the library XML code. And those passwords even seem to be interwoven with each other. As to the licensing. I believe there exist Key generators to fake-license LabVIEW installations. Never mind that most of those key generators have also some stealth load inside, that packs a few viruses and/or troyans on every computer they are executed on. After all why should a hacker who doesn't respect intellectual property respect someones privacy?

In order to deal with LabVIEW Variants on the C side of the fence you need an API that exists but is undocumented so far for people not working at NI. LabVIEW Variants are really C++ type objects so with just flattening or whatever you won't get far. And the way to pass variants to the Call Library Node is not as Interface To Data but simply as LabVIEW data. So any of the other three options though it won't really make any difference which you chose as they don't apply to data other than arrays or handles.

Where does the licensing scheme even remotely touch password security of VIs? Anything license related is really handled in the LabVIEW kernel itself so not sure what the ability to unlock a password protected VI would do there. Following is not directed at you Shaun but at anyone being high in the arms about the insufficient protection password protected VIs give them to protect their oh so precious IP: Password protection of diagrams is not meant to protect your IP. There exists only one really secure way to protect your IP, and that is to put it in a heavy steel safe, destroy all copies of your idea and dump the safe in the North Pacific above the Mariana Trench. Save of some alian race with super high tech, nobody will be able to get at those secrets. Chances are however high that someone else has already developed the same idea independently and will go to market with it and earn some money with it. Another slightly less secure means is to hire a whole army of lawyers who will involve anybody into a legal battle who might even just appearing to try to steal that IP, so that they can fight for the rest of their life, robbing them of any time to invest into monetizing the stolen idea. Both of them are highly unpractical and costly! Get over it and accept that password protection of diagrams is only to keep out the nosy. If you do need to protect your IP don't distribute the source at all! Bite the bullet and remove at least the diagram. Yes it's inconvenient as such VIs can only be loaded into the LabVIEW version in which it was created and also only on that platform but anything else means LabVIEW has to be able to get at the diagram somehow without knowing the password (or worse yet store the password in the VI somehow too) and that also means that anybody with enough determination will be able to circumvent any kind of protection the LabVIEW developers can come up with to prevent others than LabVIEW itself to get at that diagram. I think the best long term protection in that respect is actually the semi annual release cycle of LabVIEW as it obsoletes any of the more promising hacking solutions each time.

I have used in the past HelpMaker from vizacc.com. It used to be a free tool but there was some hickup in who is going to maintain it some time ago. Not sure about the current state, it got confusing and I haven't used the tool in a while.

I'm not sure this is turned off by default, but I don't like autoinserted feedback nodes at all. Yes they are equivalent to shift registers, (since about 8.5 even in performance) but I prefer the more familiar shift register added explicitedly by myself than an automagic feedback node that is in my case in 99% not what I want.