Creating shared variables bound to I/O Aliases

Hello,
I'm running LabVIEW 2012. When I right-click on an .lvlib in the project explorer, there's a "Create Bound Variables" option. It's really convenient, as it automatically binds many variables to generic network-published shared variables simultaneously.
However, it doesn't seem to support network-published I/O Aliases -- those libraries just don't show up in the dialog. I know that the I/O Aliases themselves work fine, because I was able to bind them manually, and then read them from my PC.
Is there a way to automate the binding process for I/O Aliases?
Thanks

Hi Joey,
It's mainly for maintainability.
I/O Variables are grouped physically by chassis and module, not by purpose. My current project is a plant controller, using 3 CompactRIO chassis (linked by EtherCAT) and 20 C-series modules. The I/O ports for a logical part of the plant can be split across different modules (and even different chassis sometimes) -- thus physical grouping is suboptimal.
Here is our simplified system architecture:
We need variables hosted on the PC server for DSC logging, but also need variables hosted on the cRIO for robustness (e.g. in case connection with the PC server is lost).
We have 2 primary reasons to create I/O Alias libraries, instead of binding directly to I/O Variables:
It lets us group the variables more logically, which in turn lets us simplify our code for programmatic variable access. It's an abstraction layer between the hardware and the code. The logical groupings also help our developers better visualize the system.
The client has not finalized their specifications, and the I/O port mappings might change. If we use I/O Aliases, we can just change the I/O Variable that the I/O Alias points to, and that's it. However, if we bind directly to I/O Variables, changing the hardware mapping will require us to change (i) the controller code, (ii) the I/O Variable that the PC variable points to, and (iii) (technically optional, but needed for readability) the I/O Variable name
Anyway, since it is possible to (manually) create bindings to I/O Aliases, I'm surprised to hear it's expected behavior that we would not see the Aliases in Project items when we use the Create Bound Variables function

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Dear Ravens,
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Data Logging a programmatically created shared variable of cluster or array datatype into citadel DB

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SV_TC.zip ‏3925 KB

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Do not forget to Mark solution and to give Kudo if problem is solved.
Solved!
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Attachments:
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Hello gak.
You should have a look at NI Developer Zone. I think you will find what you want.
I give you this link to begin.
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National Instruments France
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Error -1950679007 when I try to create shared variable binding automatically

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I'm using LV 8.5 with DSC.
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Picture about problem is in attachment.
The error codes are found here:
http://zone.ni.com/reference/en-XX/help/371361D-01/lverror/shared_variable_error_codes/
Other useful information:
http://digital.ni.com/public.nsf/websearch/2E8BAD0EA218A7558625712E0003F044?OpenDocument
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Attachments:
error_19506790071.jpg ‏88 KB

Hi,
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With Regards,
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Creating SV lib.JPG ‏28 KB

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I have never had to resort to creating Shared variables programatically so I will leave that for others.
I would cheat.
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I am in the process of migrating a large distributed (multi-workstation) automation system from the LabVIEW 7.11 DSCEngine on Windows XP to the LabVIEW 2009 Shared Variable Engine on Windows 7.
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Kevin Roche
Advisory Engineer/Scientist
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I have found the answer to part of my question -- an relatively easy way to create a "remote" library of shared variables that connect to the master library on my gateway workstation.
Export the variables from the master library as a csv file and copy that to the remote machine.
Open the file on the remote machine (in excel or the spreadsheet app of your choice) and (for safety's sake) immediately save it with a name marking it as the remote version.
Find the network path column (it was "U" in my file).
replace the path for each variable (which will be either a long file path or a blank, depending on the kind of variable) with \\machine\'process name'\variable name
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NOTE the single quotes around the process name; they are required.
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Save the CSV file.
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Close the properties box, save the library, and then export the variables to a new CSV file.
Open the new CSV file in Excel, and scroll sideways to the NetworkrojectBound field.
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The second one is Network:URL. That needs to be set equal to the value for each line of NetworkrojectPath.
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Save the edited CSV file.
Go back to the remote library, and import variables from the just-edited remote library CSV file.
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Kevin Roche
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Vestigial fields when exporting shared variables

Hello,
Is this a bug? I have a network-published shared variable that used to have aliasing enabled. After I cleared the "Bind to:" field and disabled aliasing, I exported its library into CSV mode. However, it still contained the columns (among others):
NetworkrojectBinding = TRUE
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The extra columns messed up my CSV parser. The only way I could find to prevent their appearance was to delete all the variables that used to have project binding, and re-create them

JKSH,
I was able to reproduce the same issue here. I'll look into this a little more and see if this may in fact be a bug.
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National Instruments
Applications Engineer

Modbus Ethernet read and write to a Eurotherm 6180XIO Modbus server using LV8.2 shared variables

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I have read many threads on related topics but none directly apply to this situation. I have created a library containing a Modbus I/O server and shared variables bound to read and write holding registers. I have followed all recommended tips for creating such variables but I can neither read or write data. All data types are U16 due to Modbus protocol limitations. I have also applied the LV x10 factor in the most significant digit in the register offset (6 digits instead of 5).
I have a cFP-1804 on the same network which reads into the datalogger OK. The registers I use are 31000 (for CH0 on module 0, 31002 for CH1, etc) and the data can be read as FLOAT32. I have updated the firmwate on the 1804 to the latest level. I cannot even get shared variables to read SGL values. Using registers 301001 for CH0 and 301002 for CH1 I can only read U16 values, and not a 2-word SGL.
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Hi,
I want to share data between a RT-target and one or more hosts (LV 8.6.1). The network shared variables are deployed to the RT-Target. According to NI accessing shared variables from another project or host has to be done by defining a shared variable on the host and aliasing it to the NI-PSP data object on the target.
I did that and the host shared variable generated an error (0x8BBB0011) during runtime.
Next I aliased to a shared variable deployed on the host from another project. This did work.
Another thing I tried was to bind the variable from the RT-target to a display element:
This is working !!! And as you can see the path of the NI-PSP data object is exactly the same ! So what is the difference between binding a data object to a shared variable and to a display element?
Is there a bug in the SVE or am I missing something here?
The host project:
The publisher VI
Hope, someone has an answer.
Regards
Matthias Quade
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Attachments:
AliasTestWrite-RT.vi ‏8 KB
AliasTestConsumer.vi ‏8 KB

Dear Mr. Quade,
thank you for posting at the National Instruments Forum. There is a known issue with the path of the bound variable with LabVIEW 8.6.1
Please download the patch for LabVIEW 8.6.1, it should solve your problem:
http://joule.ni.com/nidu/cds/view/p/id/1255/lang/de
Best regards from Munich
MarianO

Error Reading a Shared Variable Array

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I am having a problem reading an array of 20 unsigned integers from an Allen Bradley ControlLogix PLC with Labview.
I have set up a shared variable for this purpose. I have set the Data Type of the shared variable to ArrayOf Unit16. The Variable Type is Network-Published, and I have check the Bind To Source checkbox. I think my problem is in the shared variable path. I have tried the following with no success:
MyComputer\ControlLogixTags.lvlib\RsLinx\ProjectX\Online\Faults\Faults
MyComputer\ControlLogixTags.lvlib\RsLinx\ProjectX\Online\Faults\Faults[0]
MyComputer\ControlLogixTags.lvlib\RsLinx\ProjectX\Online\Faults\Faults[]
MyComputer\ControlLogixTags.lvlib\RsLinx\ProjectX\Online\Faults\
MyComputer\ControlLogixTags.lvlib\RsLinx\ProjectX\Online\Faults
I have created a simple vi for testing. I have wired the shared variable to an indicator which is an array of UInt16 items. When I run the vi, I get an error which says "Error 91 occurred at Variant to Data in Text.vi. Possbile Reason: The data type of the variant is not compatible with the data type of the input."
Does anyone have a suggestion as to what I am doing wrong?
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Phil,
In order to determine that you can correctly communicate with your OPC server, I would suggest creating a shared variable bound to a single tag. It sounds as if you already have an RSLinx I/O Server in your project library. Now you can create a new shared variable and use the browse option to browse the items of your I/O server. Be sure to select a tag that has a known value such that you can verify successful communication.
Also, does your VI utilize a dynamic data conversion? The error code mentioned (error 91) is normally associated with this data type. Our next step will be to look at this VI once we can establish successful communication. I hope this was useful for you. Please let me know if I can be of further assistance.
Mike
National Instruments
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Binding shared variable in executable across network

I can't seem to get a shared variable to bind from an executable on another computer back to a source variable on the main machine.
I can get the remote variable to change with programmatic access. Is it possible to have shared variables in an executable bind to a PSP URL on another computer? This is labview 2011.
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What I don't understand is why after binding to a specific URL, the "Shared Variable Deployment" screen of the application builder makes the target "my computer".
I probably could get this to work if I changed the network address of "my computer" in the ini file created in Application Builder?
This seem a strange way for this binding process to work. If the absolute target (for shared variable bound to another variable and referencing "absolute") was retained when the VI goes through the application builder, it would make for sense.
I can't get this to work any way with using bound variables. The only way this works is using programmatic access to shared variables in the built app, and I don't consider this the same thing.
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Creating shared variables bound to I/O Aliases

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