Remote Front Panel Problems and Best Practices

All,
Problems
I'm currently attempting to host a Remote Front Panel from a cRIO 9073. The intent of the front panel is to control and configure the services running on the cRIO. Currently I've been experiencing quite a few problems getting this to operate smoothly.
These are the problems I'm currently experiencing.
* Front panel takes a very long time to load (~45 Seconds).
* On close the front panel may reset the cRIO.
* Front panel may cause excessive CPU usage.
* Plugin has problems in Firefox.
I'm fairly sure that I've installed all of the Latest NI software (I'm using LV 2009f2)
I currently cannot post the code as it's proprietary.
Currently the front panel consists of two timed loops one running at 500ms intervals and the other running at 1000ms intervals. The GUI is basically a tab control and on the heaviest tab contains about 15 buttons.
Questions
Is it not possible to use event structures in embedded LabVIEW? So far I've had to code my own event loop to handle all the events I wish to process on the remote front panel, and I feel this might be causing a problem.
Is the sort of functionality I'm trying to achieve acceptable in Web Front Panels?
It seems that the reason it takes very long for the VIs to load is that the VI Front Panel Server must fire up. Is there a way to make this or whatever the component is that handles it fire ahead of time?
Thanks for your time, I look forward to discussing this.
Regards,
Ken

Hi Ken,
Is this a remote front panel for a real-time VI? Is it built into an executable? If this is a RT VI, you cannot use event structures. More details are available in this KB:
Can I Use the Event Structure in LabVIEW RT?
I assume you have seen this?
How Can I View Remote LabVIEW Real-Time Front Panels in a Web Browser?
Are you still having the cRio reset issue and CPU usage increase?
Kristen H.

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Remote Front Panel Problem

Hi
I am using a TAB control in a VI that is published as Remote Frontpanel.
When changing TAB the controls are often grayed out in the browser even when they are not in the running LabVIEW VI !
A Combo box may also contain the apps default values instead of the values from the running VI !
Any hints to solve this ?
I have login/logout in my application, and i need to auto logout when the last Remote Front Panel User disconnects.
How do I detect that there is no listeners/clients ?
The "connection manager.vi" is password protected, so i can't get any hints from there !
Best Regards
Teddy

I see thank you. Very funny because i thought i had to do something with duplicating the real time target.
So regarding the above problem, is there any way to be connected remotely to the target and when the link is broken to reconnect without affecting the operation of the VI running?
For example, lets assume we connect to a remote front panel which has a simple VI with just a 1 second period timed loop running and for each iteration of the loop i monitor and i save the index of the loop. When i connect to the VI i request control and i click run. The VI starts running. After one minute, at loop iteration 60 the link between the host and the target breaks. The VI should continue running.
After 1 minute of broken link the network is again available.
What can i do to re-establish connection without affecting the VI operation and continue monitoring the VI. If reconnecting after 1 minute i will be expecting to see the loop iteration to be 120 and keep running. Is there any way to do this?

UI Defaults Import problems and best practice for using UI defaults

Hi,
I'm hoping some of you experts can tell me how to Import the UI Defaults from Schema A and Workspace A to Schema B and Workspace B. My goal is to fluidly share the UI defaults with another developer as we march forward creating new versions of the application (inside new Workspaces with new schema names). My longer term goal was to create a "library" of UI defaults that other future developers could easily access as well.
The basic setup I have been using is that each developer gets their own schema and their own workspace. When a new version of the database design is made, I keep the older versions of the workspaces and schemas intact and then create a new workspace and new schema for each developer (just two of us right now). Then we Export apps, respectively, from our old workspaces and Import apps into our new workspaces. I also create a new db tablespace and new db user account and map to new workspace as well. This way I always know what db design version we are using against what Apex app version and can, conversely, delete tablespaces, user accounts, workspaces and Apex schemas in one swallow without worrying about getting the wrong version of something accidentally deleted. 9It may seem like I am doing a lot of extra work, but my sanity is still (relatively) intact.)
I keep getting
"ORA-20001: GET_BLOCK Error. ORA-20001: Execution of the statement was unsuccessful. ORA-20001: You do not have access to the schema that you are importing. Import failed. <pre>begin wwv_flow_api.g_id_offset := 0; wwv_flow_hint.g_schema := 'MY_OTHER_SCHEMA'; wwv_flow_hint.check_schema_privs; end;</pre>"
when I try importing it.
We want to share our UI defaults that we each set up in our respective workspaces and schemas. We do have some overlap of tables (which may be a no no I suppose). We also each have differently named (test) apps.
So, like app Import/Export, I thought I could just Export my app (along with UI) from Schema A and Workspace A and simply import it into Schema B and Workspace B and then in the new Workspace have access to the UI. I tried editing the UI *.SQL using the app ID and new schema name but it still balks. It seems like there is an internal table ID code specific to each table that is particular to the table and the workspace it was created in.
I can go to a specific workspace, create a sample UI, Export it's app, and Import the same app (new ID) into same workspace and the UI shows up fine.
So, what good is the UI defaults if you can't carry them forward to the next version of your app that is in a new workspace? It seems like we are forced into creating the equivalent of one workspace, say the "Library", and both of us with separate schemas sign into here. But then how do I get the UIs from the "Library" to our "Beta" workspace, and similarly from there to 'Production' without recreating UIs each time? And, if I prefer a sample set of records, say only 100 test recs, and the other developer prefers a full set, say 30,000 recs, and we have to use the same workspace, since the workspace can only be associated with one db tablespace, how can I load both 100 and 30,000 recs into same area? (and since we can't, that is another reason we wanted to use separate workspaces and pass our respective UIs back and forth and finally into the shared "Library" area.)
Well, thank for reading through this and hopefully it makes sense.

OK Scott, let me try to clarify here:
Regardless of what reasons I have, my immediate goal is to sucessfully Export the UI Defaults from Schema A and Workspace A and Import into Schema B and Workspace B.
So, logging in as Schema A into Workspace A, I go to my app, then Export/Import then "Export User Interface Defaults". There is only one schema available to choose from in the "Schema" dropdown select list. I export the UI and save it to a file.
Next I logout and then login as Schema B into Workspace B. I go to Shared Components UI Defaults and display my tables. Most of these tables (about 30 of them) have the same exact name as the tables used by the other schema. UI Defaults do not exist.
I choose "Import" in the Tasks list, File Type "User Interface Defaults" and pick file I just exported. File is successfully Imported. Now I'm on screen for installing the UI Defaults. When I try to Import the UI it brings me to "Confirm Replace UI Defaults" and lists the OLD workspace schema (not the new one I expected)as being removed and replaced. I push ahead, tell it to do the replace and get the "You do not have access to the schema that you are importing". So I guess I'm doing something wrong.

Configuring Remote Front Panels on a Real-Time Target,smart camera,but there is no image in the web page.

I do see the web page, but the image itself is not loading.i know a problem is with the installation of the LabVIEW ActiveX plug-in or the IMAQ ActiveX plug-in. The LabVIEW ActiveX plug-in is required for ALL remote front panel viewing, and the IMAQ ActiveX plug-in is needed for VIs that use the Image Display. how can i do ?where can i get the the IMAQ ActiveX plug-in. help me！

Got it working, after much experimentation. Seems to require installing exactly the right combination of items on the RT target, as some items (web services? web configuration? the "application web server"?) apparently run a separate web server - or instance of the web server - on port 80, which prevents remote front panels from being served on that port.

Remote front panel reconnection problem

Hello,
I have created a real time application build for myRIO and i can succesfully run it as startup. After MyRIO reboots, through the Project Window i select Operate/Connect to Remote Panel. I enter the local network IP address 192.168.0.101 and port 8000 and the Front Panel of the Startup VI opens. I run it and everything is running as expected.
This setup is installed on a UAV and acquires data from scientific instruments all data is writen on a USB flash drive on myRIO
It is expected that sometimes the local network link will break during the flight. To simulate this i unplugged myRIO from the ethernet cable will the Data is saved.
I noticed the following strange things:
1. At time X i connect to the remote panel and i start the DAQ which acquires data
2. At time X+10 minutes i unplug the ethernet cable which connects myrio to the local network
3. At time X+20 minutes i poweroff myRIO
I was expecting that after the connection was broken the VI would have kept acquiring the Data until myRIO powers off.
Instead i noticed that myrio acquires data for only 1 more minute after the ethernet cable is unplugged.
It is very important that after the UAV takes off whatever happens to the network connection the VI keeps acquiring data for as long myrio is powered on.
I also tried the web publishing tool but i could not connect using a browser. It seems that the web server was not running properly. I also noticed that the html file was not located in the target destination folder. I tried to manually copy it using a map networked drive but the file could not be copied.
I will appreciate any help on the above issues.
Thank you,
Christos

I see thank you. Very funny because i thought i had to do something with duplicating the real time target.
So regarding the above problem, is there any way to be connected remotely to the target and when the link is broken to reconnect without affecting the operation of the VI running?
For example, lets assume we connect to a remote front panel which has a simple VI with just a 1 second period timed loop running and for each iteration of the loop i monitor and i save the index of the loop. When i connect to the VI i request control and i click run. The VI starts running. After one minute, at loop iteration 60 the link between the host and the target breaks. The VI should continue running.
After 1 minute of broken link the network is again available.
What can i do to re-establish connection without affecting the VI operation and continue monitoring the VI. If reconnecting after 1 minute i will be expecting to see the loop iteration to be 120 and keep running. Is there any way to do this?

LabVIEW Remote Front Panels and WebCT or Blackboard Integration

Hi,
Has any one had any experience with getting LabVIEW Remote Front Panels working with WebCT or Blackboard E-learing software?
Generating the Remote Front Panel is easy enough, it's incorporating the Remote Front Panel into WebCT or Blackboard that am interested in?

Hi,
Are you using FieldPoint 6.0.2? We have a Corrective Action Report (#125870) for the remote front panels for the cFP-2220 with LabVIEW 8.6 and FieldPoint 6.0.2. R&D is currently working on a fix, until then, the only known workaround is to using LabVIEW 8.5.1.
Regards,
Jeremy_B
Applications Engineer
National Instruments

Do you need a web browser and internet server to run LabVIEW remote front panel?

Does anyone know if ones needs an internet server to use the Remote Front Panel application of LabVIEW, or is it also possible to use a LAN/WAN for the same application? if it is possible, how does one set up such a system?

You can do this on any IP based system (which includes LANs).
Basically, you need to be able to ping the server and to have the RFP port allowed in the firewall.
Then you need to enable the option in the application. If this is an executable, you will need to configure this in the Options dialog or copy some lines from the LabVIEW.ini file into your EXE's INI file. You will also need to take the htm file created by the publishing wizard and make sure it points to your VI and that it is located in a place where it can be accessed from outside the server (read the LV help or search the site for more on this).
Then, you just need to enter the URL for that htm file in the browser on the client (e.g. 192.3.42.5/c/rfp.htm) and it should load.
Try to take over the world!

Problems with Remote Front Panel

Hi, I've seen "How to create a LabVIEW Remote Front Panel" video of Grant H.
I've followed the steps to create a remote front panel but doesn't work. When I open the URL in Explorer, show the title, header and footer but don't show the front panel, only a image that say: "Downloading front panel 0.00% of 0 Bytes" and don't work.
My Remote Front Server in turned on and I'm using LabVIEW 2010 in Windows 7.

I am having the same issue.
Is there anything I can look up to find possible solutions?
BTW, I run the same application in a different machine and it works just fine. I just can't seem to find where I should be looking...

How can I close a remote front panel by closing only the browser window?

I control a remote front panel in a browser (from the client PC). If I don't use the 'close' - button in my program to end the remote front panel, but instead of this the 'x' of the browser window (in the right bottom corner), my program won't be close, it continues on the server. Do you know how to end a VI by closing only the browser windows?
Thanks for any help!
wolfe

I found the examples. Thanks.
But I could not find a solution yet. Now I know how to end a VI by clicking on the x of the VIwindow.
My problem is, to end a VI by clicking on the x of the BROWSER window after I loaded and controlled a remote panel VI in a browser (e.g. IE).
If you have any ideas ... I'd be happy.
Thanks for your help.

Crio to host multiple remote front panels

Hello all,
I've a question abt remote front panel hosted by a cRIO system (cRIO9068 to be more specific, running RTOS).
I have a top level VI (main) as the start up vi in my cRIO system, and it would call a subvi during run. I'd like to enable remote front panel for both the main vi and the sub vi so that I can see both front panels using a web browser. I'm not sure if such a configuration is possible at all and would like to listen to comments by users who have similar experiences.
Thank you very much!
Best,
Jidong

Hello hhaamm,
To the best of my knowledge, I don't believe it is possible to host multiple remote front panels from the same executable, and, if it is, would be very difficult. The NI Web Server configuration file only specifies one port on which an executable can run web services, like remote front panels. In, short, I am not sure how you would be able to accomplish this.
Another thing to keep in mind is that what you want to accomplish can be done in many different ways that would be much easier than creating multiple remote front panels.
One of these is to move all of your controls and indicators to the top level VI. i.e. make the data you want to see from the sub-VI an output of the sub-VI and create a new indicator for this on your top-level front panel. This way you can still use a remote front panel and can use different decorations and labels to separate the top-level and sub-VI outputs.
Another way to do this is to use the tab control to create multiple tabs, one for your top-level indicators, and one for your sub-VI indicators. This would still enable you to use remote front panels and would allow for the separation of your different indicators. Here is a note on how to do that:
http://zone.ni.com/reference/en-XX/help/371361H-01/lvhowto/creating_tab_controls/
And here is a more in-depth forum post on how to create them:
https://forums.ni.com/t5/LabVIEW/how-do-you-create-tabs-on-the-front-panel/td-p/201495
The final way I can think how you would accomplish this is to use a web service instead of remote front panels and host the output of the sub-VI as a separate website.
Hope this helps!
Collin D.
Applications Engineer
National Instruments

Hi,why I have a "DMA hardware error detected" when I try to save file as *.htm for remote front panel application?

Hi,
I try to learn how to present my data anywhere by using labview remote front panels. I use PCI-mio-16E-4 device to acquire data. After I start web server and try to save to as *.htm file, I got the "DMA hardware error detected" message. Can anyone help me to solve the problem. Thanks.

What was the actual error code?
Copyright © 2004-2015 Christopher G. Relf. Some Rights Reserved. This posting is licensed under a Creative Commons Attribution 2.5 License.

Error accessing Remote Front Panel on RT Target after upgrade to LV2011

I'm upgrading a real-time application (target is a desktop PC running the LabVIEW real-time) from LabVIEW 2009 to 2011. Under 2009, it was possible the view the main VI remotely by browsing to a static HTML page that embedded the front panel. After upgrading to LabVIEW 2011, instead of the front panel image I get an error saying "Server does not support Remote Panels." I have already gone through the list of possible causes from "Server Does Not Support Remote Panels" Error When Connecting to Remote Front Panel, and none of these resolved the problem. I am using the standard LabVIEW web server, there is a direct ethernet cable connecting my computer with the real-time system, and I have recreated the web page to reference the correct plug-in version. I reformatted the RT system and then did a clean install of the components from LabVIEW 2011 (using the Add/Remove Software feature in Measurement and Automation Explorer). I also created a new test project with a new simple VI; I was able to access that VI remotely on port 8000, but not on the default port 80 (which used to work under LabVIEW 2009). What changed in the web server between LabVIEW 2009 and 2011? Can I use the standard HTTP port 80 to serve a static page with an embedded VI, or does this now only work on other ports (and if so, why)? Will I need to recreate my entire project in LabVIEW 2011 in order to get this working at all?

Got it working, after much experimentation. Seems to require installing exactly the right combination of items on the RT target, as some items (web services? web configuration? the "application web server"?) apparently run a separate web server - or instance of the web server - on port 80, which prevents remote front panels from being served on that port.

Why does refreshing my web browser page increment the number of users connected to my Remote Front Panel?

Hi,
I'm using LabVIEW 2010 and a cRIO-9118 to broadcast my RT Front Panel on the web with a Web Server.
I successfully configured the web server to be able to control my Front Panel remotely. However, I have an issue with "Refreshing" the browser.
When I press "Enter" to search the adress of the web server, the number of users connected seems to increment by one and then tells me that "Too many users are connected to the front panel". Once this has been done, the only way to "unlock" the web server is to reboot the cRIO.
Is there any solution to avoid this behavior?
My current web browser is Internet Explorer 8.
Thank you
Mathieu Veillette, Ing Jr.
Solved!
Go to Solution.

Hi Mathieu,
Unfortunately, there currently isn't a very good solution for the problem you are facing. It seems like this is a known issue that R&D is working on. It so happens that in addition to simply refreshing, this issue also occurs if you try to access the Remote Front Panel using a second tab in a tabbed browser. One "fix" would be to invest in a higher count Remote Front Panel license. If that's not feasible, then the current recommendation would be to avoid connecting to the Remote Front Panel from a second tab or refreshing the view in your browser. Once you exceed the number of connections to the Remote Front Panel, you will have to restart the RT controller -- there isn't a way to change this default behavior. You can track any fixes by R&D by keeping note of the CAR (corrective action request) ID for this issue, which is #202702.
Sanjay C.
Embedded Software Product Manager| National Instruments

How to display remote front panels of subvis that are already open

I inherited an RT project that uses remote front panels for nearly all the user interfaces. The host application opens a remote front panel the the top level RT vi, and there are several subvis on the RT system that are opened from that top level vi and thus displayed on the host (i.e. their "Show Front Panel When Called" properties are set TRUE).
If the Host loses its connection to the RT system when any subvi front panels are opened, and the host application is restarted, it can re-open the top level vi remote front panel, but all the RT subvis that are already open will not display their front panels. I am looking for a way to open the front panels to these subvis from the host application.
The kicker is, I need to know which subvis are actually running before I attempt to open remote front panels. Is there any way to determine what subvis are actively running (and not just in memory, such as subvis that won't get executed until the top level vi reaches a certain state)? I am thinking that I could create a list of the subvis that I need access to, check to see if any are actively running on the RT system, and then invoke a remote front panel connection with those that are running.
Does anyone have any ideas as to how I might be able to do so? Or any other suggestions? [and yes, I know that RFP communication is probably not the best way to go, but we're too entrenched in this software to start over with a new system!]

TurboPhil wrote:
If the Host loses its connection to the RT system when any subvi front panels are opened, and the host application is restarted, it can re-open the top level vi remote front panel, but all the RT subvis that are already open will not display their front panels. I am looking for a way to open the front panels to these subvis from the host application.
It might be possible to work around this behavior by placing VI invoke nodes in your top level VI that reference each of your subvis and setting the Wait Until Done invoke method to false. This should cause the subvi to close when the top level VI closes even in the case of an unexpected restart.
You can access this invode node in the functions pallet by selecting Application Control » Invoke Node and also selecting Application Control » Static VI reference. Wire the Static VI Reference to the vi reference input node and double click the Static VI Reference and select the appropriate subvi in the dialog window. Left click on the Method section of the invoke node and select Run VI. Finally right click on the Wait Until Done invoke method and select Create Constant and ensure this constant is set to false.
TurboPhil wrote:
The kicker is, I need to know which subvis are actually running before I attempt to open remote front panels. Is there any way to determine what subvis are actively running (and not just in memory, such as subvis that won't get executed until the top level vi reaches a certain state)? I am thinking that I could create a list of the subvis that I need access to, check to see if any are actively running on the RT system, and then invoke a remote front panel connection with those that are running.
You can access this information by using the Real-Time System Manager (Tools » Real-Time Module » System Manager). This can be used to show what VIs and subvis are loaded into memory and which are running.
For more information on using this tool please referere to this Knowledge Base article.
Message Edited by BLAQmx on 02-18-2008 11:40 AM
Mark
LabVIEW R&D

ASK remote front panel

hai bro i try to remote panels with labview 8.0 professional with this information :
http://zone.ni.com/devzone/cda/tut/p/id/4791
http://zone.ni.com/devzone/cda/tut/p/id/3277
and it's done, for example i give it name test then i start the web server it's works well.
but when i try to connect again with remote panel connection manager and open the project (test)
the remote panel connection manager says that they can find it certainly i've save and open it with the same name and folder where i save the project.
can youm tell me why i can't do that?
tanx before, sorry for bad english

What do you do differently the second time from the first? Are you opening it up differently? Are you using an executable? It doesn't look like it from your description but if you are there is a link below that may help. do you have a firewall up or a proxy server? The second link may help if the problems are being caused by one of these.
KnowledgeBase 3U5H27MY: How Can I Use Remote Front Panels With LabVIEW 8.x Executables?
KnowledgeBase 2ZAC2IEG: Remote Panels Through a Firewall or Proxy Server
Vince M
Applications Engineer

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