Dear Sir,
I captured the communication trace for the EasyOPCClient Demo with screen capture as well as Prosys OPC Client Demo. Please unzip and check the attached file.

The following is the rough description of my pc setup.

The demo client is install in my laptop with the following specs
1. Windows XP Professional 32-bit OS SP 3
Intel Core 2 Duo CPU 1.8Ghz, 2GB Ram

First, my pc is setup to join my company domain, i did not create and join the workgroup as in the OPC Server. I have created a user with same user name as the OPC server and client, and have set the same password used by the OPC Server. I have also configure under components services->Computers->My Computer->Right Click Properties->COM Security

Under Access Permissions (Edit Limits & Edit Default)
I have added the newly created user and have enable the Local Access and Remote Access

As for Launch And Activation Permissions (Edit Limit and Edit Default Settings)
I have added the same user and enable local launch, remote launch, local activation, remote activation

Then i have added the same user as local administrator for the machine.

The following are the steps that i have done in the easyopc demo client after the opc analyzer have been setup and connected to my opc server (Rosemount Tank Master).
EasyDAClient.ClientParameters.
ServerStatusCheckPeriod = -1;

Step 1: Under Machine Name: localhost
Step 2: Click Browse Server, select OpcTestLab.OpcAnalyzer and click OK.
Step 3: Click Browse Item, expand the root on the left, after a while it shows Tanks, devices and system. Expand the Tanks, it shows Tanks, devices and system. I have expand the devices node and system node, which shows "tanks, devices and system" as well.

The following are the steps i have done in prosys demo client.
Step 1: Host: localhost
Step 2: Select OpcTestLab.OpcAnalyzer.1
Step 3: Click Connect after connected under Server Status message will be shown, you may refer to the screen capture.
Step 4: Click Add, a group will be automatically added.
Step 5: Under Set the properties of the OPC Group i have kept the default settings.
Step 6: Click the broswer button where the OPC Server Address Space box will pop up. The root shows OpcTestLab.OpcAnalyzer.1 and the branches shows Tanks, Devices and System. When i expand the branch under Tanks, it shows the actual Tanks that we have it in our plant, which is correct.

The main difference in steps in EasyOPC Client is there is no connect and disconnect button in the interface. I assume, EasyOPC Client will automatically connect to OPC Server once the ProgID is selected.

thank you
regards

Dear Sir,
As usual i have tried to compare different OPC Client, i am able to broswe the server using prosys opc client and commserver opc viewer. Anyway, i like to solve the issue here, as we are looking for a dotnet client which is easy to use. And i find that opclabs quickopc is one of them.
The website for the opc server that we are using can be found here. (www.rosemount-tankradar.com/software_list.aspx?productArea=1&product=30&category=10), but i am not able to find any demo. The opc server is one of the option provided by the software there are other communication module such as modbus available. Maybe the only option left is installing an opc analyzer to monitor what data is being exchange between the opc client and server. Please send me the opc analyzer and instruction on how to setup the analyzer, client or maybe configuration on the opc server. And may i know if the opc analyzer must be installed on the same machine as the opc server? Or remotely on the same machine as the opc client? I would prefer the latter. I do not want to mess up with the production system.

thank you.

Dear Sir,
We aer using Rosemount TankMaster OPC Server not sure if there is any demo. Might be switching to MatrikonOPC, i have tried setting the EasyDAClient.ClientParameters.ServerStatusCheckPeriod to -1 in the demo application, in mainform before InitializeComponent(), not sure if its the right place to set the static property.

After setting the static property, recompling and runing the code, there is another issue. When i select the appropriate server and broswe the item, the demo application will not be able to correctly view the item when i expand the branch. The root will show three branches, Tanks, devices and systems. When i expand the Tanks branches it will shows recursively Tanks, deveices and systems branch. The correct display should show TK-xxx Tank information under the Tanks branch. What other properties / codes should i add other than the above mention must be should be set for enabling the opc client to correctly iterated.

And may i know if QuickOPC Client supports reading of String Tags?

Dear Support,
I am running on Windows XP Professional and had managed to changed the COM / DCOM Settings under Administrative Tools->Component Services->Right Clickk on My Computer->Default Properties->
I have enable both DCOM and COM Internet Services, default Authentication Level set to None and Default Impersonation Level set to Identify. After changing the setting i am able to connect to the OPC Server, but another error occur. After selecting the correct server class, and click on the browse items button and after expanding the root folder on the right and expanding the tank there is another error occurs.

The error message is OPC operation Failed: "Server failed. This error originates in the OPC Data Access Server. A vendor specific fatal error has occurred within the server. The server is no longer functioning. The recovery procedure from this situation is vendor specific. The application will try to reconnect to the server after a configurable period. Techinical information: The call to IOPCServer::GetStatus on the OPCServer object has returned OPC_STATUS_FAILED in the OPCSERVERSTATUS structure."
Do you have any idea what this error is about, when using prosys opc client, i am able to browse all item and group, select the item and monitor the tag.
I have attached the screenshot of the error for your information.
regards
chee leong