Labview on Shared Variable
Hi,
In our application we want share the some IO's in Tablet PC(remote PC) and HOST PC.
We are using real time controller in our application.
For this purpose we have create shared variables in *.lvproj. While we craeting shared variables we can not assign DATA type as a cluster of different elements to the shared variables.
Due to this we created *.ctl file of that cluster and then tried to assign the same cluster to the particular shared variable.
There are nuamber of shared variables in this application with different cluster of elements.The problem is that the same *.ctl file assign to two different shared varialbles which we not required. Because we have created different *.ctl files for two different shared variables.
Is our apporach is right?
Can we use *.ctl file as a data type as cluster of different elements for shared variable?
Please suggest ....
Thanks in advance
I believe your approach is correct.
Share Variables use the data type. So if you have a number of controls with the same type of cluster, e.g. Cluster1 is String & Numeric, Cluster2 is String and Numeric, then when you assign the Shared Variable to Cluster2 it will be identified as Cluster1.
This is a reported bug in shared variables.
One workaround would be to change the data type e.g. Numeric in Cluster1 may be INT16 while Numeric in Cluster2 may be INT32.
Then the Shared Var's will identify them as different data types.
DOK
Similar Messages
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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.
I have about 600 tags which represent data or IO states in a series of Opto22 instruments, accessible via their OptoOPCServer. There are another 150 memory tags which are used so the multiple workstations can trade requests and status information to coordinate motion and process sequencing. Only one workstation may be allowed to run the Opto22 server, because otherwise the Opto22 instruments are overwhelmed by the multiple communications requests; for simplicity, I'll refer to that workstation as the Opto22 gateway.
The LabVIEW 2009 migration tool was unable to properly migrate the Opto22 tags, but with some help from NI support (thank you, Jared!) and many days of pointing and clicking, I have successfully created a bound shared-variable library connecting to all the necessary data and IO. I've also created shared variables corresponding to the memory tags. All the variables have been deployed.
So far, so good. After much fighting with Windows 7 network location settings, I can open the Distributed System Manager on a second W7/LV2009 machine (I'll refer to it as the "remote" machine henceforth) and see the processes and all those variables on the Opto22 gateway workstation. I've also created a few variables on the remote workstation and confirmed that I can see them from the gateway workstation.
Now I need to be able to use (both read and write) the variables in VIs running on the remote workstation machine. (And by extension, on more remote workstations as I do the upgrade/migration).
I have succeeded in reading and writing them by creating a tag reader pointed at the URL for the process on the Opto22 gateway. I can see a way I could replace the old DSC tag reads and writes in my applications using this technique, but is this the right way to do this? Is this actually using the Shared Variable Engine, or is it actually using the DataSocket? I know for a fact that attempting to manipulate ~800 items via Datasocket will bog down the systems.
I had the impression that I should be able to create shared variables in my project on the remote workstation that link to those on the Opto22 gateway workstation. When, however, I try to browse to find the processes on that workstation, I get an error saying that isn't possible.
Am I on the right track with the tag reader? If not, is there some basic step I'm missing in trying to access the shared variables I created on the gateway workstation?
Any advice will be greatly appreciated.
Kevin
Kevin Roche
Advisory Engineer/Scientist
Spintronics and Magnetoelectronics group
IBM Research AlmadenI 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
where machine is the name or ip address of the master (gateway) workstation (I used the ip address to make sure it uses my dedicated automation ethernet network rather than our building-wide network)
and process name is the name of the process with the deployed variables visible in the Distributed System Manager on the gateway machine.
NOTE the single quotes around the process name; they are required.
The variable name is in the first ("A") column, so in Excel, I could do this for line 2 with the formula =CONCATENATE("\\machine\'process name'\",A2)
Once the formula worked on line 2, I could copy it into all the other lines.
Save the CSV file.
Import the CSV into the remote library to create the variables.
Note: at this point, if you attempt to deploy the variables, it will fail. The aliases are not quite set properly yet.
Open the properties for the first imported variable.
There is probably an error message at the bottom saying the alias is invalid.
In the alias section, you'll see it is set to "Project Variable" with the network path from step 4.
Change the setting to "PSP URL" with the same path and the error message should disappear.
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.
You'll notice it is False for the first variable, and true for the rest. Set the field FALSE for all lines in the spreadsheet.
Scroll sideways... you'll notice there are two new columns between NetworkrojectPath and Network:UseBinding
The first one is NetworkingleWriter; it should already be FALSE for all lines.
The second one is Network:URL. That needs to be set equal to the value for each line of NetworkrojectPath.
You can accomplish this with a formula like in step 4. In Excel it was =U2 for line 2, and then cut and paste into all lines below it.
There is a third new field, Path, which should already be set to the location of the variable library. You don't need to do anything with it.
Save the edited CSV file.
Go back to the remote library, and import variables from the just-edited remote library CSV file.
Once you have imported them and the Multiple Variable Editor opens, click on done.
You should now be able to deploy the remote variable library without error. (Make sure to open the Distributed System Manager and start the local variable engine. It took me a few failures before I realized I had to do that before attempting a deployment).
Voila! You now have a "remote" library of shared variables that references all the shared variables on the master machine, and which should be deployable on other machines with very little difficulty.
It actually took longer to write out the process here than to perform these steps once I figured it out.
Kevin Roche
Advisory Engineer/Scientist
Spintronics and Magnetoelectronics group
IBM Research Almaden -
LABVIEW 2012 - shared variable error during programming of NI CRIO 9023 and TPC 2212
HELLO,
i am using CRIO 9023 with TPC 2212 and LV 2012. I want to develop a stand alone app which has a front panel on TPC. at first i am building a simple app with two controls variables, one is a sliding bar on TPC Vi and the other one is the while loop variable "i" on CRIO VI. i used shared variables.
first i creat shared variable on CRIO side and access this on TPC Vi. I COMPILE both Vi,s and they are working fine. But when i created the slide bar control in TPC VI, compiled and deploy the TPC Vi, it get deployed in TPC. But when i start compiling the CRIO VI an error mesage occured as follows;
I have tried every option to best of my understanding like formating crio then installing all softwares including Network variable engine etc. i also go in properties of the executable file of TPC Vi and go in properties-shared variable- then check the "deploy variable in application" option . below is image displayed.
I am in despirate need for solving this problem as i have to develop the final app for testing soon. can some one help me regrarding this.
REGARDSI would not recommend using shared variable engine. It is supposed to make things easier, but in fact, you will spend more time troubleshooting why it is not working than you will actually coding an alternative solution.
Try the Simple TCP Messaging instead.
http://zone.ni.com/devzone/cda/epd/p/id/2739
Machine Vision, Robotics, Embedded Systems, Surveillance
www.movimed.com - Custom Imaging Solutions -
How can I use an Access front end and Access button to control a LabView Shared variable boolean?
My company has invested a lot of money on the office network to write many many access databases and front ends. I'm looking for a way to tie a button on an access front end to toggle a LabView boolean shared variable to notify me when they changed something on their side of the network. I'm not seeing anything that helps on a web or forum search. They don't like the idea of a separate labview control that they have to push a button on to let me know.
Thanks
Solved!
Go to Solution.Hi Patrick,
While this is not the intended purpose of Network-Published Shared Variables, you might be able to accomplish this by writing separate accessor VIs for reading from and writing to the variable, making sure to wire the inputs and outputs. Then, you could build a DLL, making sure that you include the accessor VIs as Exported VIs and include the DLL Library in the Always Included section of the DLL Build Specifications. During this process, you will define the function prototype, which will provide the function call, required parameters, and return values. Once the DLL is created, you can then call it and its functions from another programming language (C, C++, C#, VB, etc.). This may or may not work, but it is the only way that I can think of at this point. I have included some references that may help you in this process.
Building a Shared Library in LabVIEW (White Paper)
Calling LabVIEW VIs from Other Programming Languages (White Paper)
Calling LabVIEW DLL From C# (Forum with Examples)
I hope this helps.
Regards,
Mike Watts
Product Marketing - Modular Instruments -
Error codes for shared variables in Labview 8.5?
I am trying to use Shared Variables in Labview 8.5 to enable real-time loops (similar to some of the examples in "Using the LabVIEW Shared Variable", published Aug 28, 2007). I created it to hold the result of a 16-channel A/D converter (so a 16-element I16 array). To avoid losing samples, I used buffering, with a buffer of 5. To test this, I made a pair of VIs, one a producer that stuffs a 16-element I16 array into the shared variable "every so often" (controlled by a timed loop), and a consumer loop that reads the shared variable and does something with the data.
If I think of the buffered shared variable as a Real Time FIFO (as the article suggests it is), I was curious how I would know (a) when the queue was empty, and (b) if the queue had overflowed. Both are necessary if this is to be a practical means of exchanging data -- you want the producer and consumer to run more-or-less at the same rate, but only the producer is deterministic. The consumer needs to be able to run "faster" if it falls behind (for example, because it is writing data to disk), but you don't want it to read data from the shared variable if there's nothing there. [One can always read a shared variable, after all -- as the article states, it simply "holds" the last value written to it].
Snooping around, I discovered that there are "error codes" associated with the shared variable. In particular, a code of -2220 (FFFFF754) seems to signify an empty queue (or a shared variable that has not yet been written to), while a code of -1950678981 (8BBB003B) appears to be "buffer overflow".
Is this documented anywhere? Are there other "error codes" that would be helpful to know? Is there some rationale to these seemingly-random numbers? [It would help to develop code to utilize shared variables if there was a bit less "magic" and "mystery" involved].
For what it is worth, with a buffer of size 40, I could generate 16 I16 values at 1 KHz (simulating sampling from a 16-channel A/D at 1 KHz) and pass it to a consumer node that (a) read from the shared variable until it was empty, then (b) "went to sleep" for 20 msec (simulating "doing something else non-deterministically"), and not miss any data (because I could then empty the Shared Variable RT-FIFO, which should have been half full, before it overflowed on me). Not bad throughput -- I bet I could push it even higher.
Bob SchorHey Bob,
The errors are documented in the LabVIEW help:
Shared Variable Error Codes
Real-Time Shared Variable Error Codes
There are several error messages for buffer underflow/overflow depending on the settings of the network or RT FIFO buffers. In particular the -2220 and -2221 are useful for the producer/consumer use case. For example (as you probably know) the consumer can flush a variable using the error code (see the attached image).
Gerardo
Attachments:
variable1.png 3 KB -
Deploying cRIO as Shared Variable Engine
I am finishing up a project where a crio will be continuously recording data and the computer is running a program that will download the data once daily as well as comunicate with the program running on crio device over shared variables. Since the crio will be using a cellular modem to connect to the internet, connection loss is expected. For this reason we have made the crio serve the shared variables so that if connection is lost to the PC, the crio will continue to record data normally without problems when it writes to or reads from the shared variables.
The crio will be running headless. I built a real-time application and deployed it as startup successfully on the crio device without warnings or errors. I connected to it via font panel to confirm it started up and is working properly. I will eventually use the application builder to build an installer that will install everything needed to run the program on the PC side. However, when I open the 'Belle Glade System PC' and run it, it attempts to deploy the shared variables on the crio device. It warns me that it will close any applications running on the crio device. This is not what I want. The shared variable engine is already deployed on the crio device and the program is running. All the PC program (Belle Glade System PC) needs to do is run and connect to the shared variable engine already deployed. I am obviously doing something really fundamentally wrong here and I could use some help.
[will work for kudos]I apologize for not posting the solution to the problem.
Basically what you end up having to do is create two nearly identical shared variable libraries, one on the pc and one on the crio. The library on the PC has each of its shared variables binded to the corrosponding variable in the cRIO Shared Variable library by PSP URL (ip address and variable location). To do this, open the PC shared variable library and go to the properties of a specific variable. Check "Enable Aliasing" and under the bind to drop down menu select PSP URL. Then hit browse and find the variable on the crio. Do this for each of the variables on the pc.
This option does not seem to be 100% reliable as it has trouble detecting connection problems between host PC and crio device. This is because shared variables look for a connection to the shared variable engine. However, both the pc and the crio have their own shared variable engine running as a host so there is always a connection as far as it knows, lol. This solution worked ok for me since I could not find a more relable option.
There is a better explaination on this post: http://forums.ni.com/t5/LabVIEW/cRIO-Shared-Variables-amp-stand-alone-application/m-p/797139?query.i...
[will work for kudos] -
Shared variable engine memory problem
Hello,
I have a lot of problems with DSC 8. The server that worked very well in DSC 7, in DSC 8 is creating a lot of problems starting with memory leaks in tagsrv process. I have over 5000 shared variables and when I publish them the tagsrv is around 90Mb of memory. After approx. 30 min is around 130Mb and so on until the computer becomes useless. If I restart the computer the process is the same, even if I don't start the VI that updates the shared variables. I tried to uncheck different things in the variables definition like: no alarming, no buffering, no scaling, with no improvement.
Is there a way to undeploy the shared variables or processes manually, not from the labview project, or Variable Manager. To undeploy the mentioned library with the Variable Manager takes more that an hour (just to enumerate all the shared variables).
Any suggestion is welcomed,
cosmincosmin,
I have several thoughts for you. First, I recommend
splitting up
your 5000 variable library into a set of smaller libraries. In
contrast
with the LabVIEW DSC 7 engine, the LabVIEW 8 Shared Variable Engine is
optimized for multiple smaller libraries. I would recommend
having at
most about 1000 variables per library. You'll see some different
recommendations from different people at NI, but in my personal
experience I
think 1000 is about as many Shared Variables that can be easily managed
at
once. For your case this would mean having 1000 variables in 5
different
libraries. --Splitting up your library gives you the added
benefit of being able to
undeploy/disable individual libraries without affecting the other
libraries. Unfortunately, the SCF migration tool will not do this
for you manually so it may take a little time to get everything
organized.
Your comment about ever-increasing memory usage is
concerning. Do
you see this while deploying your library, or while writing
values? If
you write to values very fast (like in an untimed loop) for an extended
period
of time memory usage will increase as the variable buffers
increase.
Please elaborate more on this topic and let me know what happens if you
separate your variables into multiple libraries. I was not able
to reproduce this on a similarly spec'd computer using 10 libraries of
500 variables each.
You can programmatically undeploy libraries using the delete process VI
on the DSC Engine Control palette in LabVIEW. Use this VI in combination
with the get process list VI to quickly remove all currently deployed
libraries.
Also, regarding your question about why variables sometimes show up the
Published Variable Monitor window; the different utilities you described may
use different methods to get that variable list. These methods behave
differently depending on how stressed the Shared Variable Engine is. If
you're in the middle of loading a library with 5000 variables I'm not surprised
that the list won't get populated immediately in the Published Variable Monitor
window. After the library successfully loads though, you should be able
to refresh the view and see all the variables.
Regards,
Nick F
LabVIEW R&D
~~ -
VI cannot find shared variable in engine despite successful deployment
I am unable to use Shared Variables to communicate between VIs located on my PC and the VIs located on my cRIO-9014. This is a new development as I have been running the same VIs for over a year without this problem. The only recent development is that the IT department at my company installed new virus protection software and changed some windows firewall settings on the PC that I am using. This problem first began as soon as I got the PC back from IT. I have since unblocked LabView in Windows Firewall but that has not fixed the problem. The error I get every time I try to read a shared variable on the real time target is:
Error -1950679035 occurred at Shared Variable Read in RT Interface.vi
Possible reason(s):
LabVIEW: (Hex 0x8BBB0005) Unable to locate variable in the Shared Variable Engine. Deployment of this variable may have failed.
I have redeployed all of my shared variables and according to LabView the deployment was successful, yet I still get this error every time. Is it likely that something the IT department did with the Antivirus/Firewall software has blocked communication between the cRIO-9014 and my PC? I have used Measurement & Automation Explorer to check communication with the device and as far as I can tell everything seems fine.After adding LabVIEW to the exceptions list of Windows Firewall, my issue seemed to be cleared up. I am now getting the same error message once again, but now I get it every time I run a VI with shared variables and it actually pops up an error message asking me to continue or stop. Again, according to LabVIEW the shared variables deployed successfully. I looked at the two KB articles that were posted and it seemed like this error has three causes:
1-Unsuccessful deployment - everything seems to have deployed
2-Firewall Issues - were taken care of to fix my original problem
3-Shared Variable Engine not running
I've looked around and I found a reference to 'repairing' the shared variable engine but not a guide for how to do that. I have opened variable manager (I am using LabVIEW 8.5) and have stopped and started the shared variable engine with no effect.
What are steps I can take to ensure the Shared Variable engine is running properly? -
Using Modbus TCP I/O Server with new DSC Shared Variables in LabVIEW 8.6
Hello,
I'm using LabVIEW 8.6 and want to communicate with a Beckhoff BK9000 Ethernet TCP/IP Bus Coupler via Modbus TCP. Instead of using the NI Modbus Library, I've tried the new LabVIEW 8.6 feature "DSC Shared Variables" as described at the bottom of this page: Latest NI LabVIEW DSC Module Features and Demos. Reading of analog input bus terminals works fine. However, I haven't figured out yet how to write on an anolog output bus terminal with these shared variables.
It's about a 16 bit analog output and I need to write to the registers 0x1121 and 0x0801. It works with the NI Modbus Library (just using function code 6 and choosing the registers), but on the other hand I don't know which shared variables I have to choose for these registers. I've tried several data items (e.g. 400001 upwards as well as 402049 for 0x0801) but none of them worked. I would be glad for a short explanation - thanks in advance for your support!
Regards
utechleThe Beckhoff documentation says, that holding registers start with 0x0800. I've checked this by using the NI Modbus Library. I used the "MB Ethernet Master Query.vi" togehter with the function code 6 for "Write Single Registers", changed the settings of the starting address to hexadecimal view and entered 801 (since it starts with a control byte in 0x0800 and the data out word follows in 0x0801). Furthermore, I had to address register 0x1121 in the same way for resetting the watchdog. As I've mentioned in my first post, this method works fine. However, I haven't found out yet which shared variables i have to use for accessing these registers.
On the other hand, it's no problem to read data from analog input bus terminals using shared variables. They start with 0x0000 (status byte) and 0x0001 (data in word) and I can read data with the shared variable and data item 300001, respectively.
Message Edited by utechle on 01-27-2009 11:12 PM -
How do you synchronize accesses to a LabVIEW Shared Variable?
I would like to create an ad-hoc weather station program (I'll explain more in a bit). I am using LabVIEW 8.0 Full Edition, and I would like to share data over a network between stations with the LabVIEW Shared Variable. Here's what I want to be able to do:
A node would start up, and begin publishing data to a network via a shared variable.
The shared variable is an array of clusters
The cluster information would hold things like:
Station Name
Station Location
Weather information cluster (temperature, rainfall, windspeed, wind direction, etc...)
Timestamp of last update
When a new node would like to enter, it would bind to the shared variable, grow the array, and add its information.
If a node's Station Name and Station Location is already in the shared variable, it would merely update the information in the cluster.
Viewing nodes could pop in, bind to the shared variable, and read/display the information at any time.
I am trying to enumerate problems with this before implementing, and I have run into a stinker of a problem that I am not sure how to solve. How do I synchronize accesses to the LabVIEW Shared Variable? If I read the variable, modify it, and write it back, I will undoubtedly run into a race condition where 2 nodes attempt to update its data and I will lose the data written by the first node - Node A reads, Node A modifies, Node B reads, Node A writes, Node B Modifies, Node B Writes, and thus the modifications made by Node A are lost. In my specific application losing some data isn't critical, but if not remedied this type of problem could cause massive amounts of data to be lost when there are numerous nodes, and that is definitely not acceptable.
Does anyone have any recommendations on how to synchronize the read-modify-write operations on the data in the Shared Variable?
-DannyWendy,
I am afraid Semaphores are not network-shared objects (to my knowledge), they are system-level objects that use operating-system synchronization mechanisms. If I were synchronizing on a single machine, a semaphore might be a valid mechanism; as an aside, most user-mode semaphores are designed to synchronize within a single process - to synchronize between processes you need to store the semaphore in the Kernel, and to synchronize over a network you would need a network node to handle serialization of requests. My Shared Variable is published over a network, and to my knowledge there are no network-published synchronization mechanisms available - mostly because there is no way to currently perform an atomic test-and-set on the Shared Variable (am I correct?) and there isn't a mechanism for blocking access to a Shared Variable from another network device/machine (or is there?). I've been looking for some way to implement an atomic test-and-set but I am running into a wall; I know that if I select the "single writer" attribute of the Shared Variable I can get LabVIEW to force a single writer allowing me to have an atomic "set", but I need more than that.
If only there was a network-shared Semaphore or some way to block other network accesses to the Shared Variable I would be in business - something like what I want doesn't exist, does it?
Thanks!
-Danny
Message Edited by texasdiaz on 02-23-2006 02:52 AM -
HI
When I put a network shared variable with fifo RT activated on my diagram, the arrow is broken.and I' ve got this message:
""LabVIEW could not generate code for the shared variable.You must open the VI in the project that contains the library where the shared variable resides""
If I uncheck FIFO RT option for this variable the arrow isn't broken anymore.
I 've no idea how to correct this weird error?
Autodeploy is on, and I've check copy / delete in diagram in tool/options\diagram
regards,
jamesHello,
I don't reproduce this error.
Could you send your VI?
Regards
VéroniqueD
NI France -
How do I install Shared Variable Engine on a computer not having Labview?
Hi,
I am trying to communicate with a real time program running on Compact RIO through shared variables. I have an executable of the host vi that runs on a Windows computer. If I run this executable on the computer that has Labview installed on it, it functions fine. I want to be able to run this executable on a computer with Labview. I learned that I have to first install Shared Variable Engine on this computer.
How do I do that? Where to install it from? Is that going to be sufficient? Please provide the solution or point me to the right resources.
Thank you.
Anmol.When you built the installer for the executable, you have a choice to include additional installers. One of them is the "NI Variable Engine". Have you tried including it?
LabVIEW Champion . Do more with less code and in less time . -
Shared Variable Engine on Windows PC w/o full install of LabVIEW
I have the NI Developer Suite (8.20) and need some conformation before I get too deep in a project.
First of all, it is my desire to become very efficient on develop compiled executables with LabVIEW 8.20 as my NI Developer Suite license allows me to deploy these programs to any number of machines without facing copyright infringement. I have been successful with this to a certain degree, but am still having problems in the testing stages of my application especially in cases where the hardware I am trying to target does not exist on my developing station. If anyone can point me to white papers that would help me get the mindset to develop in this way, I would appreciate it.
Onto the topic of this post:
I am just scratching the surface of the shared variable interface that is available in LabVIEW 8.2. My project involves two computers where both of them need to share variables back and forth from each other. I've been reading everything I can get my hands on and I am having a hard time answering my unlying question: Is it possible for both of these machines to be running compiled LabVIEW programs and still manage the shared variables between them? That is to say, can one of the machines have the Shared Variable Engine running on it as a Windows service, or compiled into my application executable.
I've read that I can access shared variables from my compiled LabVIEW application through NI-PSP. I am wondering what my limitations would be sans-LabVIEW installation other then the troubleshooting head ache you get from developing applications without direct access to the hardware.
Thank you for your time and submissions.
-NickerbockerI am trying to get the "Shared Variable Client - Server" project example compiled so that both the server and client vi's can be run as executables on a standalone machine.
I have created 3 build specifications:
1. "My Server" which is the compiled EXE of the server.lvib. Added that entire library to the source.
2. "My Client" which is the compiled EXE of the client.lvib. Added that entire library to the source.
3. "My Installer" which is the installation package of the vi's and NI supporting software. In the additional installers I have added:
* NI DataSocket
* NI LabVIEW Run-Time Engine 8.2
* NI Measurement & Automation Explorer 4.1
* NI Variable Engine
* NI Variable Manager
* NI-DAQmx 8.3
Some of those are added for future needs. Installed the package on my target machine and run the server executable it appears to run fine but I get various error messages from my client.exe package (which I won't go into detail here, yet). Upon stopping the server I get the message "LabVIEW: (Hex 0x8BBB0005) Unable to locate variable in he Shared Variable Engine. Deployment of this variable may have failed."
I check the services running and see that the "National Instruments PSP Server Locator" and the "National Instruments Variable Engine" are both in the list and "Started." I open up the Variable Manager that has been installed on my target machine and manually add the "waveform" and the "command" variables under a process I call "server" and start the process. After that I start my server.exe that I have compiled from the server.lvib library. The process gives no error messages until the stop button is pressed, and then I receive the message "LabVIEW: (Hex 0x8BBB0011) The connection to the server was disconnected."
The compiled programs run fine on my development machine as well as the uncompiled VIs within the LabVIEW development enviornment. Something tells me that I simply do not have the Variable engine properly configured on my target machine. Also, the process and variables should automatically be populated under "Local System" in the Variable Manager, right? I do not need to add them manually, or do I?
Thanks for your input!
-Nickerbocker -
I/O direction of LabView shared variable?
Can I programmatically change the I/O direction of a LabView shared variable? I'm using LV 2010 and I'm trying to change the I/O direction of a NI 9403 module programmatically. Is this possible?
Hi JAF,
I'm assuming your intended purpose is to input and output data through the same DIO line.
In that case, I would recommend using a case structure. You would need to create a case for input data and another case for the output.
Below is a link describing the characteristics of a case structure.
http://zone.ni.com/reference/en-XX/help/371361G-01/glang/case_structure/
I hope this helps. BTW, are you using a cRIO? I'm just curious.
Regards,
Josh L.
Applications Engineer
National Instruments -
LabVIEW 8.0 Run-Time engine & shared variables
Has LabVIEW 8.0 Run-Time Engine the shared variable's support, I wonder?
The thing is that .exe with globals/locals runs alright, but beeing replaced with shared variables it refuses to run.
What's wrong? May be need in library(s) absend?
Thanks.You can use the Shared Variable in the Run-Time Engine (you do not need DSC).
Can you be more specific about what happens when it refuses to run? Are you seeing an error message?
If you are using Network-Published shared variables, they need to be deployed before you run the application. You can either deploy them manually with the project, or your application can programmatically deploy them. You can find some more information about this in the LabVIEW Help under "Shared Variables and Stand-Alone Applications or Shared Libraries" (follow this link and scroll down to the bottom):
http://zone.ni.com/reference/en-XX/help/371361A-01/lvconcepts/project_variables/
-Chris
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Where to look for the computed stats collected using gather_table_stats
I have used analyze command before but new to gather_table_stats. I have executed gather_table_stats procedure as given below. Now where to look for the statistics estimated and also what are the important parameters I need to look in the stats ? Any
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Cancel System Error Messages from RWB
Hi All, I have nearly 3000 messages those were got System Error in Integration Engine process, but when i check messages in SXMB_MONI all are success and written to target folders also.There is no problem absolutely. Now i just want to cancel those S
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My Philips hdtv plasma wont display my pb
Please help. I had a regular hdtv before and never had problems. I have pluged to my 12" mini-dv adaptor, pluged to that is the DVI. Now at the other end of the DVI, I have a HDMI adaptor. My tv just stays black. I Called philips and they said try ch
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ED not captured at header level
Hi I have created condition record for excise duty with JMO2,but at the time of GR,Ed is is capturing at item level but not at header level Can anybody solve this isues
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All my other versions in the past, if left open at shutdown, were relaunched upon startup. Not CC2014. I am running Yosemite.