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Live Binding doesn't work on 'Progress Bar'

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01 Aug 2013 10:40 #1367 by dtomov
I will try to provide You access to the OPC Server, but I want to send You the settings over PM (private message) , but I don't see this option in this forum.

If You want You can contact me at e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. and I will reply with the settings how to connect to the OPC Server I'm using.

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29 Jul 2013 14:31 #1366 by support
I have checked how ReadParameters from Live Binding are processed, and found no problem, i.e. when one selects "Cache", it appears that indeed am OPC Read from a Cache is invoked.

It could be that the problem is not so straightforwardly linked to the Cache/Device as it seems at first glance.

Can we get a hold of the OPC server for our test here?


Yes, an "error" (an exception) means that no value/timestamp/quality could be obtained from the OPC
server - and therefore there is no OPC Quality to speak about in case of error.

And yes, with our component you need to use the ReadItem method in order to get access to the full quality value. The ReadItemValue WAITS (or times out) until the quality becomes Good, but you do not get the quality value from it.

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25 Jul 2013 13:01 - 25 Jul 2013 13:02 #1365 by dtomov
Thank You for Your fast response and I'll wait for Your answer sometime next week. :-)

Here is what I get when trying to read from Device:
 
{"An OPC operation failure with error code -1073430509 (0xC004C013) occurred, originating from 'OpcLabs.EasyOpcRaw.DataAccess.RawEasyDAClient'. The inner exception contains details about the problem."}
 

The inner exception details show the following:
{"Read not completed. This error indicates that it could not be verified that the requested read operation was completed during the timeout period. It is possible that the read operation will actually succeed or fail, but later. Increase the timeout period if you want to obtain positive or negative indication of the operation outcome. Other reason for this error may be that under  heavy loads, topic request or response queue is overflowing. Check the event log for queue overflow errors (if event logging is supported by the product and enabled). "}

I tried to make the timeouts longer , but that gave no different outcome/result.

Receiving the exception means that i didn't receive bad OPC quality, right ?
Also to receive the OPC quality I suppose I need to use ReadItem Method , not ReadItemValue Method ?
Last edit: 25 Jul 2013 13:02 by dtomov.

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25 Jul 2013 12:41 - 25 Jul 2013 12:44 #1364 by support
I will check whether the ReadParameters are properly interpreted in Live Binding. I am now leaving the office and will be back on Monday, thus please allow some time for the answer.

And, out of curiosity, what happens if you read from Device? Do you get some kind of Bad OPC quality, or an exception?

Best regards

(below, attempting to attach your last PNG, converted to JPG)

Attachments:
Last edit: 25 Jul 2013 12:44 by support.

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25 Jul 2013 10:11 - 25 Jul 2013 10:14 #1363 by dtomov
Yes, You were right. I set the RequestedDataType to I4 and now is working.

Now I have other issue:

I'm trying to read a value 'short integer' from an OPC Server (RcWare Vision of Domat Control).
And when trying manually to read a value through written programing code I have success only when implicitly specify that i want to read from Cache.

That I suppose is a server issue (reading is successful only from cache).
But when i do Live Binding and specify reading from cache I can't read the value.

I'm using for the probe simple Windows Form Application with one TextBox.
Here are the settings of the LiveBinding:

dox.bg/files/dw?a=7924ae6b56 ( again PNG wasn't let to upload )

Here is the working code, that successfully reads from cache:
ServerDescriptor myOpcServer = new ServerDescriptor("ESG.OPCServer.RcWareDA.1");
DAItemDescriptor myItem = new DAItemDescriptor("0.DOBRICH.TIS1.Inverter 1.INV01-Energy-Total.Output value[1_1_28_15]");
DAReadParameters myParam = new DAReadParameters(DADataSource.Cache, 1000);
 
_cut_
 
	private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = easyDAClient1.ReadItemValue(myOpcServer, myItem, myParam).ToString();
        }
 
Last edit: 25 Jul 2013 10:14 by dtomov.

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24 Jul 2013 14:29 - 25 Jul 2013 12:54 #1361 by support
Hello,

you can see the ProgressBar working with LiveBinding, if (under our group in Start Menu) you run the Live Binding Demo.

Most likely reason for your problem is that the ProgressBar.Value is an Int32, but the canonical type of the OPC item you are binding is VT_R8 (a floating point - double). Floats cannot be generally converted to integers by the binding mechanism. In order to overcome this, in the Binding properties->Source->ItemDescriptor, set the RequestedDataType to I4.

Note: I have now "relaxed" some of the upload setting for the Forums, so hopefully the PNG upload will work next time.

Best regards,
Zbynek Zahradnik

(below is the image from your previous post, as JPG)

Attachments:
Last edit: 25 Jul 2013 12:54 by support.

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24 Jul 2013 08:37 - 24 Jul 2013 08:40 #1360 by dtomov
Hi to all.

I have the following problem:

I'm using VS2010 (also tried VS2012) and Live Binding on TextBox is working for example,
but when i try to Live Bind a Value to a ProgresBar it doesn't work.

I attach a screenshot of the settings for the Live Binding.
I'm using for the test - OPCLabs.KitServer.2
and item "Boilers.Boiler #1.Pipe1001.ValveX001.Input" .


For some reason I can't attach the image so i uploaded here dox.bg/files/dw?a=6c6d19ebe4 .


As I said when bind is done to TextBox value get refreshed every 1 second, but on ProgressBar I have no change.

Thank you for your time.
Last edit: 24 Jul 2013 08:40 by dtomov.

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