HELP!!! Does LabView support a thin client or dumb terminal (diskless workstation) type of deployment

[pglover]

Hello,

Does LabView support a thin client or dumb terminal (diskless workstation) type of deployment? I have a need to run LabView on some sort of dumb terminal / diskless workstation.  If someone has deployed LabView in this matter, please provide me all the details on how this was accomplished (software, hardware, etc.)

Thanks

[tst]

You can run an LV built application without installing anything (at least before 8.0), but there are some limitations. You have to be on a supported platform, so I'm not sure whether this fits your requirements.

To do this, you basically need to have the proper DLLs in the same directory as your exe. Most notably, this would probably be LVRT.DLL, but you may need some others. If you need stuff like DAQ or VISA I don't think that a DLL would help and you might have to install.

There is a module for building LV applications on PDAs (either Palm or Windows CE), but you should be aware that this module is still limited compared to the desktop version and still has a significant number of bugs.

As another option, you could try LV for Linux. Officially, it's only supported for certain releases of Linux, but it might run on others. There was a thread recently in the LAVA forums about running LV on DSL, so I would suggest you search for it.

The last option that comes to mind at the moment is the LV embedded module, but you probably don't want to go there as it's quite complex and expensive.

If you tell us what you actually want to do we might be able to help more.

[pglover]

Ok...

I will try to explain the situation to the best of my knowledge. There will be instrumentation in a lab that is connected to PLCs. I am anticipating 30+ instruments, each containing it's own PLC. I plan to setup a dedicated server running LabView to read the data from the PLCs using OPC, logging the data to a database management system (like Oracle), and monitoring (sending out alarms/alerts via email for unnormal activity). This server will be in a computer room and not the laboratory. The PLCs will be connected to the network via TCP/IP. So the OPC server will be able to see all the data from the 30+ PLCs.

Now in the lab where the instrumentation is housed, I want to use dumb terminals or thin client PCs running LabView (from a Citrix or Windows Terminal server) to control and read data data from the instruments. Each dumb terminal, will see and control 5 PLC instruments. The dumb terminal will be connected to the network. How can I run LabView on the dumb terminal? What about Citrix or Window Terminal server?

[tst]

Since you have a windows server, the easiest thing would probably be to use the windows terminal services client to connect to it remotely. Every version of windows (including PocketPC and CE which run on PDAs and thin clients) includes it. That way, you don't need anything installed on your client.

The other option would be to write a program on your client which would communicate either with the PLCs directly or with the LV program running on the server. If your terminal is running CE, you will need to buy the LV PDA module to write the program. If it's running Linux, it might work, but my suggestion would be to get just one of the more expensive terminals which can run XP and use it to connect to all the PLCs instead of having 6 or 7 terminals (assuming of course you can do that). The way to do this would be to place a Wi-Fi access point in the lab (assuming you can do that too, of course) and use it to have a wireless connection to the terminal.

To do the first kind of program, you can search this site for "Modbus". There are some implementations of modbus client VIs floating around, but I believe they're all based on VISA, so you will either need to install that or convert them to use the TCP functions.

To do the second kind, you would need to implement some sort of protocol which will allow your client\s to talk to your server program. Search the example finder for "TCP" and this site for "messaging protocol" to see some good examples of this.

[pglover]

tst....

I am a LabView novice, and I don't understand your solution to my problem. Can you please call me directly so we can talk about the solution you are offering me. Here is a phone number where you can reach me (804)-307-8663.

[tst]

Sorry, can't call you.

My first suggestion has nothing to do with LV. It is simply connecting as a remote client to the windows server and controlling the windows session on the server.

My second suggestion involved writing a program which will contact the PLCs directly using Modbus and get the data from them. As mentioned, you can find some Modbus client implementations for LV by searching the web (or, if you have LV 8 and the DSC module, I think it should come built in).

My third was writing 2 programs - one would run on the server and one on the client\s. The server program would be responsible for sending the data to the client and the client would be responsible for interacting with the user and sending the appropriate messages to the server. I already gave you pointers on what to search for (the example finder can be found by going to Help>>Find Examples and the site can be searched from the box at the top of the page, but make sure you don't search just the forums).

In both cases, you would need to design the program and the interface for the user.

Wi-Fi also has nothing to do with LV and is simply a way to form a wireless network. Any mobile device would almost definitely have support for it and buying an access point to form the wireless network is easy and cheap.

To learn more about LabVIEW, I suggest you try searching this site and google for LabVIEW tutorials. Here, here, here and here are a few you can start with and here are some tutorial videos. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide and the LabVIEW user manual (Help>>Search the LabVIEW Bookshelf).

[pglover]

tst.

It looks like option 2 and 3 involves running a program on the client workstations. Once again I want the client workstations to be diskless dumb terminals. I am trying to eliminate the need for these client terminals to be full blown PCs with XP or has an operating system installed like XP. It looks like what you are suggesting for Option 2 and 3 involving a client PC running an OS like XP....

[tst]

Every device has an OS of some sort. Otherwise, it would just be a screen. You can get PDAs running PalmOS or PocketPC and use the LV PDA module to write code for them, but that is not necessarily a good option, as I mentioned previously.

You can get tablet PCs running Windows CE, Linux or XP. Devices running CE often have the OS burned onto some onboard ROM and have an additional expansion card or a flash HD. Devices on which you can run Linux or XP will probably only have a flash drive.

In any case, I don't know of any dedicated client which can simply let you connect, and definitely not one you can run an LV application. LV is only supported on a limited number of platforms. Again, it sounds to me as if your best option is getting a tablet PC running windows CE and using the terminal services client to connect to the windows session running on the server.

[pglover]

tst...

Let me clarify something... When I said running LabView, I mean running a LabView built application, and not the LabView development application....

[tst]

That was what I was refering to. You can only run LV built applications on a limited number of platforms. For most of these, you would need to have the LV run-time engine installed (or at least present as a DLL, as I said in my original post). The other option is basically a windows CE or PalmOS device, where you can run applications built using the LV PDA module without having the LV RTE installed, but the device will have to have one of those.

The only option you have for running LV on hardware which doesn't support it is using the LV embedded module and that's really something you don't want to go into as it's rather expensive and complex and not meant for what you're thinking of.

The bottom line - LV applications can only be run on Windows XP, Mac, Linux, Windows CE or PalmOS. There are some other options like the Pharlap OS, but that's not relevant for you.