Design issue with sharing LV2 style global between run-time executables

Question

Hi,
Just when I though that I had everything figured out, I ran into this design issue.
The application that I wrote is pretty much a client-server application where the server publishes data and the client subscribes data using data sockets. Once the client gets all the data in the mainClient.vi program, I use LV2 style (using shift registers) to make the data global to all the other sub-vi’s. So the LV2 is in initialize mode in the mainClient.vi program and then in the sub-vi’s the LV2 is in read mode. Also, I had built the run time menu for each sub-vi that when an item is selected from the menu, I would use the get menu selection to get the item tag which will be the file nam
e of the sub-vi and open the selected sub-vi using vi server. This all worked great on my workstation where I have labVIEW 7.0 Express installed. But the final goal is to make exe’s for each of these sub-vi’s and install runtime on the PC’s that do not have labVIEW installed. Of course when I did that only the mainClient.exe program was getting the updated data from the server but the sub-vi’s were not getting the data from the mainClient.exe. I did realize that the reason for this is due to the fact that I had compiled all the sub-vi’s separately and so the LV2 vi is now local to each executable (i.e. all executables have their own memory location). Also, the run-time menu did not work because now I am trying to open an executable using vi server properties.
To summarize, is there a way to share LV2 style global's between executables without compiling all of the sub-vi’s at one time? I tried using data-sockets (local-host) instead of LV2 st
yle gloabls to communicate between the sub-vi’s but I ran into performance issues due to the large volume of data.
I would really appreciate it if anyone can suggest a solution/alternative to this problem.
Thanks
Nish

Answer 1

> 1)   How would I create a wrap-around for the LV2.vi which is
> initialized in my mainClient.vi and then how would I use vi server in
> my sub-vi to refer to that LV2.vi?
> You mentioned that each sub-vi when opened will first connect to the
> LV2.vi via via-server and will keep the connection in the shift
> register of that sub-vi. Does this mean that the sub-vi is accessing
> (pass-by-reference) the shared memory of the mainClient.vi? If this
> is what you meant I think that this might work for my application.
>
If the LV2 global is loaded statically into your mainClient.vi, then any
other application can connect to the exe and get a reference to the VI
using the VI name. This gives you a VI reference you can use to call
the VI. Ye
s, the values will be copied between applications. That is
why you need to add access operations to the global that returns just
the info needed. If you need the average, do that in the global. If
you need the array size, do that in the global. Returning the entire
array shouldn't be a common operation on the LV2 style global anyway.
> 2) Just to elaborate on my application, the data is
> transferred via DataSockets from the mainServer.vi on another PC to
> the client’s PC where the mainClient.vi program subscribes the
> data (i.e. 5 arrays of double type and each arrays has about 50,000
> elements). The sub-vi’s will have to access these arrays
> located on the mainClient.vi every scan. Is there any limitation on
> referencing the mainClient.vi data via vi-server from each sub-vi?
Your app does need to watch both the amount of data being passed across
the network, and the amount being shared between the apps. You might
want to consider puttin
g the VIs back into the main app. What is the
reason you are breaking them apart for?
Greg McKaskle