Khalid

October 3rd it is.. countdown's begun: http://www.ni.com

-Khalid

What is a .DBC file? Can you please elaborate?

-Khalid

Thank you for sharing the VI.

Here's some good info' on Property Nodes versus Local Variables:

http://zone.ni.com/public.nsf/websearch/74...47?OpenDocument

Regards,

-Khalid

Yes, the INI seems to be the only (and the right?) place to fix this. Has worked for me for a while now.

-Khalid

You will have to send the data from the PXI to DSC box via TCP or DataSocket. And then use Memory Tags on DSC.

Hope this helps.

-Khalid

Hi,

How are you acquiring the data on the PXI? If it's DAQ data, you could use DAQ-OPC.

Regards,

-Khalid

You could also use the 'Get Panel Image' method on the VI and the 'Write JPEG file.VI' to do this:

You will have to supply the correct reference to the VI whose image you want to capture.

-Khalid

All you need to do is participate in our first official LAVA coding challenge.

Hmm.. every participant gets a t-shirt and a mug? Or am I thinking wishfully?

-Khalid

I plan to use DataSockets to be the OPC Client and I have the spec. for the target OPC

server and need to write a Labview device driver.

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Hi Bill,

Will there be other clients commnicating with this device? I am just wondering, if it's only LabVIEW that will be communicating with this device, you can write the device driver for it in LabVIEW and use it as-is in the client portion of LabVIEW (without making it an OPC Server). Writing an OPC Server in LabVIEW is definitely more difficult than an OPC Client. And that too without proper documentation and device to test.

As for the OPC OpenG toolkit, I am not sure if it will be infringing upon DSC Copyrights. May be we should start a discussion for this on OpenG.

Regards,

-Khalid

Hi,

The following thread show you how to use DataSocket Read VI to read a HTML page and then to parse out the required raw text. As for the writing to file part, you can check out the File IO examples in LabVIEW.

http://lavag.org/top...ndpost__p__4760

Hope this helps,

-Khalid

Hi Everybody...

I use LabView for many applications.  And whatever our clients need.  I may attempt writing a video game for fun... 

JLV

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Ditto here .. including the games for fun

-Khalid

Hi,

When you're using property nodes, you're only affecting how you display the string. Yo are NOT actually modifying the string itself. Thus you're "losing" the underline when you concatenate the strings.

You will therefore need to use the property node for the final string indicator. And to underline character(s) from within the string, you can use the Selection Start/End property. See the following thread for more on this property:

http://forums.lavausergroup.org/index.php?showtopic=437

I am attaching the modified example (saved in 7.1.1).

Hope this helps,

-Khalid

Download File:post-311-1124166966.vi

Is the OPC server from Kepware more "friendly" to use with LabVIEW?

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Not sure how a friendlier OPC Server would help...? Because with DataSocket (and DSC) ruled out, I don't see any other way of making LabVIEW an OPC Client. Unless of course you plan on making your own OPC Client and calling it from within LabVIEW.

Is there inetrest enough for an OpenG "OPC VIs" project?

Regards,

-Khalid

This may not be exactly what you are looking for, but is (hopefully) good info' in general:

Benchmark Execution Speed of LabVIEW Applications

It has the following quote, for instance: "... 3 to 10 times reduction in development time you benefit from when you develop applications in LabVIEW..."

I personally have developed both in C/C++ and LabVIEW and agree with the above statement, especially when it comes to measurement and automation systems.

Regards,

-Khalid

Please take a look at the Online Help for calling DLLs from LabVIEW. Also, search NI's support site for articles and examples.

Khalid Ansari

Sorry, more questions than asnwers:

How are you writing to the OPC Server? DataSocket?

And if the Server is expecting 16 bits, can't you split your data into 16 bits?

Khalid Ansari

The Registry Key seems to be the way to go. See the following Microsoft article for details:

http://support.microsoft.com/kb/328010/EN-US/

Regards,

Khalid Ansari

I am having some trouble setting multiple writers and write access on data socket items that are not predefined through the data socket manager.

As far as I remember, these settings can, unfortunately, be only set from the Data Socket Manager.

Regards,

Khalid Ansari

For completeness sake, here's an article on the difference between Value Property Node and Local Variable:

http://digital.ni.com/public.nsf/3efedde43...47?OpenDocument

Regards,

Khalid Ansari

You may also use the 'Microsoft Internet Transfer Control' in the ActiveX container and read the HTTP info' as String data (from a Variant).

Here's the diagram which should give you the idea:

http://forums.ni.com/attachments/ni/170/83366/1/https.png

Regards,

Khalid Ansari

Also, the lack of extensibility and compatibility with new technologies will spell the demise of PLC's.

This is true and is already happening.. with FieldPoint first, and now even more with CompactRIO .

Traditional PLC manufacturers too are moving towards such devices what are now called PACs -- Programmable Automation Controllers. See the following for instance: http://gefanuc.com/pac

Khalid Ansari

I need to develop a network distributed application for data monitoring and control so i must create the comunication protocol.

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Hi Alessandro,

This is not a direct answer to your question... just want to make you aware of an existing product -- the Datalogging and Supervisory Control (DSC) module for LabVIEW, which has built-in networking functionality for monitoring and control.

Please visit the following page for more info' on the LabVIEW-DSC module:

http://sine.ni.com/apps/we/nioc.vp?cid=10418〈=US

:question: Why re-invent the wheel? You should take into account the development AND maintenance time for the really-proprietary networking protocol. I guess it depends on how big/small of an application you're developing.

Regards,

Khalid Ansari

Hi gsussman,

Here's something that might be a solution for such situations -- ghosting . We use this for testing various combination of OSes and product versions. Ghosting, for those who do not know, is the process of backing up the entire partition of a hard-disk as an image which can be later restored. Symantec has this product called Norton Ghost which does this and which we have been using successfully for a while now.

The idea is to have two hard disks, or at least two partitions. Let's call them System and Data. System is where your OS is installed. And all those products which you want to ghost. Data is where you store data, and your ghost images.

You can now create images with combinations of the right versions of LabVIEW, FieldPoint, and anything else that needs to be with this combination. You can have many such images with different combinations of LabVIEW and other driver software, and save them on the data disk.

Using Norton Ghost, you can restore any of these images as your system partition. Common files can be on the Data partition. You can also have programs which don't have effect on your development combo on the data disk, like your email client, for instance. However, note that since the System partition has the OS, almost all programs will have some files on that partition (which is fine).

Whenever there's an issue which requires a particular combination, you fire up that combination and you're good to go :thumbup:. The restoring (and ghosting) process is pretty fast -- few minutes. You can also compress the images (takes a little longer though) and burn them onto CDs, or store them on the network.

As I said earlier, we do this on our test system. You could dedicate a machine for such "old issues." But I don't see why your development machine cannot have this. Ghosting the development machine itself from time-to-time seems like a good idea.

In the passing, I must mention that Windows-XP has this feature called "Restore Points" which may sound like a good alternative, but it doesn't restore user files/data. The list of files it restores can be found in: systemroot\System32\Restore\Filelist.xml

Hope this gives you some ideas.

Regards,

Khalid Ansari

Hi,

You would start with the examples (\examples\instr\smplserl.llb). If the examples do not give you the desired results, try the loop-back test. For RS-485, on one of the ports you would short pins 4 and 8 together, and 5 and 9 together, thus connecting RX+ to TX+ and RX- to TX-. Whatever you write to this port should be looped-back to you. You may use the 'Basic Serial Write and Read.vi' example for testing this. This should eliminate any issues with your multimeter and test the card and the serial drivers first.

If you haven't already seen this, here's a troubleshooting tutorial on NI's website:

http://zone.ni.com/devzone/conceptd.nsf/we...29?opendocument

Hope this helps,

Khalid Ansari

Hi,

On your sub-VI which has the baud-rate Control, connect this Control to the connector pane making it one of the inputs. (If the baud-rate is a Constant on the diagram, you will replace it with a Control on the front-panel).

Then, in your top-VI, add a Control to the panel and wire its terminal to the baud-rate input you just created on the sub-VI. (Or, an easier option is to right-click on the baud-rate input you created and select Create Control. This will add the Control to the top-VI's front panel.)

Hope this helps.

Khalid Ansari