Use shared variables with FPGA device on Host PC

Hi all I am having a frustrating problem. I am trying to use shared
variables linked to a cRIO 9012. The shared variables were created and
then written to in a RT vi. is there any way I can assign locations to
these not within a RT vi. I altimately need to run the Host vi on a
TPC-2512 touch panel computer and I can't run a RT application on that. I
just need the variables to update without the RT vi running and I can't
figure out how to do that, if its even possible. Here is what I have so
far. Thank you in advance for your help.
Attachments:
PumpMonitoringDevice.zip ‏2083 KB

Adam:
You may be able to use arrays to speed up your program, but bear in mind that the TPC is pretty much guaranteed to be slower than your computer (as it's likely to have lower system specs).
You'll want to use the array manipulation functions to combine and retrieve your data (most useful will likely be "Build Array" and "Index Array," see context/LabVIEW help for more details). Once you have the data in an array, you can likely pass it through a shared variable configured for an array datatype.
I'm not sure if/how much of a speed boost it will give you, but I think it's definitely worth trying. If you're not sure about the speed, try simply cutting your variable count in half and see what kind of speed increase you get with the same amount of code but fewer variable values being transmitted through your network connection.
Good luck!
Caleb Harris
National Instruments | Mechanical Engineer | http://www.ni.com/support

Similar Messages

How to use shared variables with native c programs

Hello
What is the way to use shared variables with native c programs?
I have a c/c++ program that uses the NIDAQmx C-API to perform measurements. Now I want to communicate to a LabVIEW program via shared variables.
Is there a C-API for shared variables as there is for the NIDAQmx functionality? Where can I find further documentation? The document "Using the LabVIEW Shared Variable" mentions that one "can read and write to shared variables in ANSI C", but there are no hints about how and where to look.
Thanks in Advance

Hi user42,
with CVI 8.0, you cannot create or configure shared variables. However, you can read or write to an already configured LabVIEW 8.x shared variable from CVI using the DataSocket API.
In order to do this you need to have and DataSocket 4.3 or higher installed.
Here's a forum post about using the DataSocket functions a LabVIEW Shared Variables:
http://forums.ni.com/ni/board/message?board.id=180&message.id=24569&requireLogin=False
With CVI 8.1 and Measurement Studio 8.1 it's possible to use Shared Variables via the Network Varaiable Library (check out the end of the "Network-Published Shared Variable" section within the "Using the LabVIEW Shared Variable" documentation and the following link).
Datasocket with LabWindows/CVI and LabVIEW Real-Time:
http://digital.ni.com/public.nsf/allkb/CC4343488413A2F586256E6200099638?OpenDocument
Daniel
NIG

Blink while alarm on using shared variables with remote panel

I am creating an application where I have front panel indicators data bound to shared variables. I also set it up to have them blink when the alarm is on. I am using the DSC module.
This works great under the development environment. But when I connect using the remote panel, I can no longer see the blinking indicator if there is an alarm. I can see the blinking indicator on the machine that is running the program, but no on any of the remote panels (I have no problems connecting to the remote panel and controlling the program).
I have the remote panel set as embedded, since I want the user to be able to change some settings over the network.
I am sure I am missing something simple, any ideas??
thanks
Kenny

I have been using IE6 and Firefox, and I have found that the blinking does show up, if you refresh the page. And then if the alarm stops and the blinking stops, you will not notice it until you refresh again.
Kenny

Using shared variables in windows 7 64 bit

Hi !
I am trying to use network published shared variables (with Labview 8.6.1) in windows 7 64 bit. I have three PCs on the network. All PC's are visible to each other. I am able to remotely log on to other PCs.
But when i run my program, the shared variables are not able to read the value over the network. The same program was working with windows XP.
I am not sure whether it is windows issue or labview issue.
Please help ASAP.
Mandar Joshi

I am having the same problem with Shared Variables with LV8.6.1 and Win7 64 in a program that uses a shared variables to share in seperate loops. I was able to use a local variable instead, but would love to know if it possible to use shared variables with 8.6.1 and win7.

Using shared variables in a rt target

Hi all,
I wrote a diesel engine ECU in LV 7.1 FPGA and ran it for the past year, using TCP VI's to communicate between the Host and cRIO-9004.
Next, I translated it to LV 8.0 (with some difficulty recompiling the FPGA) and it worked fine up to that point.
Next step was to use the much-touted shared variables to eliminate all the TCP overhead. I defined 2 shared variables as big clusters with lots of controls and data passing back and forth. This worked fine while running under the source code. However, once I compiled the Host and cRIO code (ECUHost.exe and C:\NI-RT\startup\startup.rtexe), the sharing stopped.
I tried defining and binding the variables under My Computer and also tried under the cRIO target, with no success. I was able to get source code to talk to compiled code (I forget which one was which), but not when both were compiled.
Thanks for any suggestions,
McSynth

That is quite strange. Here is some information regarding shared variables and building stand alone applications that may or may not help:
Using Shared Variables in Stand-Alone Applications or Shared Libraries
If you plan to distribute a stand-alone application or shared library (DLL) that uses shared variables, do not include the .lvlib file in an LLB, the executable, or the DLL. Use the Source Files Setting page of the Application Properties dialog box or the Source Files Setting page of the Shared Library Properties dialog box to change the Destination of the .lvlib file to a destination outside the executable, LLB, or DLL.
Best Regards,
Jaideep

How to use shared variables to address multiple Watlow controllers on the same COM port

Hello,
I am trying to use LabVIEW 2010 to control 4 Watlow temperature controllers on one COM port. 3 are Model 96 and 1 is an EZ zone controller. Each controller has a unique modbus address, and I am trying to read from and write to individual registers (such as closed loop setpoint) using shared variables. I am getting return data when reading (although the data appears to be invalid), but am unable to change the value in the register by writing. How can I be sure that the Modbus server is sending commands to the correct controller?
Chuck
Solved!
Go to Solution.

Peter,
Thanks for the reply. I have actually solved that problem. I realized that the Modbus server address has to be the same as the controller's Modbus address.
I have, however, run into another problem. Perhaps you could help me with that. I have a system with 4 Watlow controllers, 3 are series 96 controllers, one is PID only and 2 are ramping. The 4th controller is an EZ zone. I am using RS485 for communications and the controllers are all wired in parallel for communications and power.
I have set up 2 Modbus servers for 2 of the controllers.
This is the first I have ever worked with Modbus based communications. I have successfully programmed using the Modbus read/write VIs, and am wanting to move to shared variables. My questions right now revolve around addressing, Modbus I/O servers and COM ports. Specifically, at this point, I know the addresses need to match up between the server and the slave device (Watlow controller in my case), how many servers can I create and use on one COM port? If the number is limited, is there a way I can specify an address that I want the server to talk to? Will the broadcast mode work to request data values from the controllers?
I'd appreciate any information you can help me with, or if you could point me to some sort of concise 'How-To' for Modbus communication.
Thanks.
Chuck

About the performance of using shared variables

Hi
My system has almost 200 I/O points,I want to the host communicates with PLC using OPC(I had create a OPC I/O Server).
If I use shared variables bind to OPC data items, there must be almost 200 shared variables.
And my puzzle is that what's the performance of using these shared variables,will they eat up memory and processor?
Another question is that if an shared variable will be time-lapse(i.e.,if an OPC data item value change feedback to program block with 0 delay or not),if so ,then how many millseconds it will delaies?

here is a paper about the performance of shared variables.
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks

How to use shared variables to measure analog input

Dear All,
I am using Real time remote system. I am using PXI-6259 card, PXI-8184RT controller and PXI-1031 Chassis.
I want to use shared variable to measure and analog Input(voltage) from
an analog input Channel. I tried attaching it with the physical
channel using the bind to source option but it idoes not seem to work,
can any one give me any suggestions?
Screen shot of this is available.
I tried using the Acq and graph example and deployed it to the RT but
the Sine wave I input in the measurement channel becomes highly
distorted when I see it in the host.vi, there is also a Screen shot of
this also. Is there any other option.
What am I doing wrong? all suggestion are highly welcome.
Thank you.
Sincerely,
Munir Afzal Bhatti.
Attachments:
SV2.jpg ‏2305 KB
SV3.jpg ‏2305 KB

You will have to give us the whole picture. What is your client computer; a PAC, desktop etc? What are you running on the client computer; a VI or an executable? Where are you going to deploy your library? On the host machine or the client machine?
If I assume that you are running a VI on the client machine and are depolying the library on the host, all you have to do is to create another shared variable and bind it to the variable on the host machine. You can do this by checking the Bind to Source option when creating the variable and browsing to the network item in options. Be sure to have the library deployed on the host side before you attempt to do this otherwise you won't be able to find the variable.
Adnan Zafar
Certified LabVIEW Architect
Coleman Technologies

How can I get a list of available shared variables from my device?

I have to develop a program to connect to many OPC ready devices. I don't have these devices yet but I have setup two PCs. One is simulating a device. Does anyone know how to read a list of the available shared variables on a device or on another PC so that I can use them later on in the program for reading and writing?
Thanks
Matt

There is a community example that lays out what I think you want to do. You can find it here:
http://decibel.ni.com/content/docs/DOC-9523
I hope that helps!
National Instruments
Applications Engineer

Coercion problem when using Shared Variable

I have a curious coercion problem when using Shared Variables. I want to share the state of a State Machine, which is an enum saved as a control (typedef) called TYPE State (see attached). I create a shared variable called State and define it as a Custom Control, using the just-mentioned typedef. So far, so good. I've attached three simple VIs -- the first one, Init State, simply wires a constant to the input of the Shared Variable to initialize it -- the wired constant is, of course, defined by the typedef. However, the Get State and Set State, meant to wire an indicator (for reading the state) or control (for setting it), develop coercion dots when wired into the Shared Variable. Why? How do I get rid of the dot? [I suppose I could abandon my typedef and custom control, but the beauty of typedefs and custom controls is that it "enforces" rules, lets you use enums for clarity, keeps the code "honest", etc. -- I'd hate to give that up just to get rid of a dot!].
On a related note, the code seems to work. This is much too simplistic to do anything, but if you open Set State and Get State, set the state to anything, run it (it immediately stops, of course), then run Get State, you'll see the chosen state appear in the indicator. So it does appear to work. The "error" (coercion dot) may, I suppose, be a "bug" in Labview because it can't figure out the mapping of the (very simple!) Custom Control, but if so, I hope it gets fixed quickly!
Bob Schor
Attachments:
Coercion Problem1.zip ‏38 KB

Hello Bob,
I am also seeing this behavior, I will escalate this question to our LabVIEW developers and post again here no later than next Tuesday, November 27th as National Instruments will be closed for the remainder of this week.
If this issue does turn into a product suggestion, I would suspect the workaround would to live with the coersion dot for the time being.
Enjoy the holiday
Regards,
Erik J.
Applications Engineer
National Instruments

Can we use shared variable in main report's crosstab

Post Author: sangi
CA Forum: General
Hi,
I have a main report with subreport (in Group footer), crosstab (in Group header).
For cross tab calculation, I need a value from subreport to be passed to main report's crosstab.
I could pass the value using shared variable.. but since the crosstab is in group header , I am not able to get the values .. .it is all 0....
Please help me

Post Author: wapper
CA Forum: General
To my best knowledge, what you ask for is impossible. The subreport in group footer is going to be evaluated during the last pass, so you are too late to get values into the group header. I could suggest creating a copy of your subreport and placing it (possibly hidden) into the group header just to get the values you need... But this would be the last measure if you really can't do anything else to achieve same goal. Wapper

How to use shared variables?

Hello..
Can anybody please guide me in using shared variables... I'm learning LabVIEW 8.5.... But did not understand how to use shared variables... I tried to read web pages regarding shared variables but got confused.... So anyone can please help me...?
Thanks for any help from you...

You will have to give us the whole picture. What is your client computer; a PAC, desktop etc? What are you running on the client computer; a VI or an executable? Where are you going to deploy your library? On the host machine or the client machine?
If I assume that you are running a VI on the client machine and are depolying the library on the host, all you have to do is to create another shared variable and bind it to the variable on the host machine. You can do this by checking the Bind to Source option when creating the variable and browsing to the network item in options. Be sure to have the library deployed on the host side before you attempt to do this otherwise you won't be able to find the variable.
Adnan Zafar
Certified LabVIEW Architect
Coleman Technologies

Configuring Database for logging to citadel Database using shared variable engine

Hello All,
I have two systems with me here, one with LabVIEW 8.5 and one with LabVIEW 8.6, I'm using Shared Variables in my code and I am Logging to citadel Database. In a PC with LabVIEW 8.5, I am able to Log Data to citadel Database, but with the same code I am not able to Log Data from the PC with LabVIEW 8.6. Both the PC's have Database Installed and the connection with the Database Exists when I test connection with database through control panel. I would Like to know any configurations (in LabVIEW or in code or in Database or in PC) that have to be done for Logging to Database because the PC with LabVIEW 8.6 was added recently and the code was upgraded to 8.6.

It was due to a dll in LabVIEW, a dll named nitaglv.dll
Now I have a issue with Data Logging from the EXE, once the shared variables are deployed programatically from the EXE the Data Logging stops,
can I get any input on this issue..???

Communicating Between Multiple LabVIEW Executables on different computer using Shared Variables

hi,
I need to develop some executables which will be launched on different computer of a LAN. Some DATA are common. I need to share the data using shared variables.
I usually used LabVIEW so I 'm familiar with shared variables but in this case, the RT target is a part of my
project.
I do I need to procceed in my case?
thanks

Ok but it's not my configuration and I haven't found my answer in the tutorial.
You speak of a case where there is a computer and a RT target under the same LabView project. As I said earlier, I often use labview RT and shared variable between computer and RT target. But I assume here it's different.
My question is : how do you acces to the SVE from 3 computers (without any RT target)?
1. If I create 3 labview projects using the same Shared Variable, do I need to use the same .lvlib on each project?
2. Is it possible?
3. How can I configure where the SVE should be? When I use a RT target, It only depends where I put my Lvlib. But here there is 3 projects.
James
Attachments:
Sans titre.JPG ‏9 KB

Can I use ICloud to store all my data and use it seamlessly with my devices and Mac?

Can I use ICloud to store all my data and use it seamlessly with my devices and Mac. I.E. I want to use it as I use my time capsule and get rid of all this stuff I have in my office.

Yes.
Apple - iCloud - Learn how to set up iCloud on all your devices

Use shared variables with FPGA device on Host PC

Similar Messages

Maybe you are looking for