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jfiddler

multiple daqfactory programs simultaneously?

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Can I run multiple instantiations of daqfactory, each running a different program and accessing different labjacks, on a computer simultaneously? Win XP, if that matters.

Thanks for any help

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I'm afraid I don't have a definitive answer for this one. It depends on many things. In general, you can have more than one copy of DAQFactory running at the same time on a single computer. With express there definitely should not be a problem. With full versions, you can sometimes run into problems if you are using the hardware key. What happens is if both copies try and validate the key at the same time, one of the copies will think the key is missing and throw up a window. Fortunately, you just say "Retry" and all is well, but it can be annoying. Truthfully, I'm not really even sure that this is an issue anymore due to some internal changes we made recently.

That's the DAQFactory side. The question then is whether the LabJackUD can handle being called from two different apps at the same time, even if those apps really are just the same app being run twice. This is the part I'm really not sure of, and you'll probably just have to try it, or perhaps the LabJack guys can address it I know that you can run into problems if you are running DAQFactory and fire up the LJControlPanel, but that may be because LJControlPanel accesses all the labjacks and does other things that only the LabJack guys know. If you kept the two apps separated, i.e. each communicating with a different labjack, then you'd probably be ok.

Finally there is the licensing issue: if you have two labjacks, then technically you have two Express licenses and therefore you are ok to run two copies simulataneously on the same PC. If, however, you run more simulataneous Express apps than you own labjacks (and therefore Express licenses), then technically you are in violation of the license agreement as you are essentially trying to bypass the limitations of Express (i.e. get 4 pages instead of 2) In the end, this is probably a moot point as I really doubt that two different copies of DAQFactory running simulataneously on the same PC can access a single LabJack at the same time. You are therefore much better off simply buying DAQFactory-Lite for $199 and saving yourself a whole lot of problems. You'll also get unlimited pages, 30 more screen components, access to other devices and other features.

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My intent is to run fewer instantiations of daqfactory express than I have labjacks, so I won't be violating my license. The reason I want to do this is that I will be controlling two separate processes. They're both pretty simple, so I'm confident that one PC can handle both, but eventually I may want to run them on separate computers. I could make them simply be separate pages, since each process needs only one display page, but I don't see how I could tease them apart later if necessary without a lot of pain, since they're not really programs that are embodied in text files that I could maintain separately.

Am I missing something? Will daqfactoryE help me to easily move some of the sequences, components, conversions, etc. into a new program at a later date?

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Yes and no. Channels and components are pretty easy. Channels you can export then import, and components you can simply cut and paste. Conversions, however, would require retyping, same with logging, export sets. One thing many people do is create a single document and then use a flag, perhaps set in the StartUp sequence, which determines which parts of the program run. This allows them to keep one code base for their application. Its appropriate if there is some commonality, but if you have two completely separate apps, I'd just run them simultaneously and see how that works. The flag method also doesn't work too well if you are using channel timing. To make it work right, you'd have to dynamically create your channels.

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Hello,

For my projects we often run multiple DAQ's on the same computer. Our experience with that is quite reliable, only disadvantage is that there is not possibility to navigate easily between both runtimes and the description in the taskmanager doesn't tell you which program is who. Therefore we developed a seperate navigation tool to use the F-keys for navigation. This works well.

Best way is to watch the processor usage, we've run 5 runtimes on the same computer and had problems with that. Easy solution is to buy a faster PC of course.

greetings Bart van Diepen,

Pro Control

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