I'm partly developing opc client application using opc.net api and I have some trouble connecting remote opc server. Below please see the code I wrote to connect to opc server.
Opc. URL url = new Opc. URL ( "opcda://network-pc/some-opc-server" );
Opc.Da. Server server = null ;
OpcCom. Factory fact = new OpcCom. Factory ();
server = new Opc.Da. Server (fact, null );
server.Connect(url, new Opc. ConnectData ( new System.Net. NetworkCredential ()));
After executing this code I am getting error: System.Runtime.InteropServices.ExternalException: CoCreateInstanceEx: Access is denied.
In addition, both computers are in the same local network, and I can connect to opc server from my computer using third party opc clients.
Is there anybody who faced with this kind of issue?
Thanks in advance.
This may not be your C# source code issue.
This could be DCOM permission issue. You have to configure DCOM permission based on your OPC Server guidance for client application.
Following documents for general reference for OPC and DCOM settings
http://www.sytech.com/download/OPC_and_DCOM.pdf
In addition to the answer from Zin Min, make sure that you are on the same domain. As cross domain connections are not possible using OPC-DA, without tunnelling of some kind.
Related
We install liferay6.2 in windows dedicated server 2008 r2. Liferay sever is working smoothly in the server but when we are trying to access it from browser then we are unable to access it. Error: server not found. In Liferay we have one portlet for video conference and it is also working fine. We can access the server through RDP(Remote Desktop) but whenever trying to access through browser fail to find the server in web.
May be this issue can be easily handle by the network admin or may be by any Liferay developer.
Does your dedicated server have a public (routed) IP address? Also, check firewalls that might block port 8080 if you have not changed the default port. As you say Liferay is running smoothly - you just can't access it - your problem is most likely rather related to the network configuration, not to Liferay itself
Just I have installed Oracle Weblogic Server and configured RESTFul Service. Developer can able use in office network but when I placed it in proxy server then It is supporting.
As per discussed with developer, need to set cross domain access control security. Can anybody help me how to I can set that from Oracle weblogic Administrator control?
Client side they are using javascript & actionscript to call that service.
I would suggest trying to use SOAP UI to test the service through the proxy service and see what the behavior is. You might want to change the proxy server to not cache the result from the URL during testing.
You can use web.xml to configure security roles and map them to WLS credentials/roles. If you have added a username and password then you should be able to test this from SOAPUI.
In our office we have setup TFS for project development. The TFS Server is WIN 2003 server SP2 with VSTFS 2008 and is running fine. Now we need to setup a TFS Proxy server on client site for client to access. Before going for the client setup, I wanted to build and test proxy in our office on a dummy server (will call it Proxy server hereon) by keeping it on a different domain. OS configuration of the Proxy server is the same as TFS server. I have installed and configured TFS proxy on Proxy server to connect to TFS Server. Also we have built trust between the two different domains to enable communication. Now problem is that I am not able to at all connect to TFS server. I am trying to connect from Internet Explorer of proxy server using proxy service account. It gives me error: The page cannot be displayed. HTTP 500 - Internal server error. The page I was browsing was http://tfs:8080/VersionControl/v1.0/ProxyStatistics.asmx.
I think I have done all the required steps correctly to configure proxy as described in MSDN and also TFS installation guide. Here Proxy service account is a member of ‘Team Foundation Valid Users’ group. I am able to connect to TFS Server (specifying port) using Telnet from command prompt on proxy server as suggested by few sites. The TFS server web sites have been configured to use Integration Windows Authentication. Event Logs on both the servers are also not giving any error. Overall I’m not able to get it done.
Any ideas on what might be the problem???
I think the port number for accessing the proxy server is 8081.
I also do not know why you need to install the proxy server on the the client side. You only need the VS200x on the client side I assume but check on
http://msdn.microsoft.com/en-us/library/ms252490(VS.80).aspx?ppud=4
I want to develop a software which restricts users internet access using vb6 or vb.net.
This is not a baby sitter program but
1) whenever a client machine takes any browser it should ask for username and password.
2)There should be option for adding new users at the server side application.
can anyone suggest any name of such a software. or some sites where I can get some help
on the same..
You could implement a HTTP proxy using sockets. You would turn off internet connection sharing on your server and configure the other machines to connect to the web via your proxy.
I would recommend going for an off the self solution e.g. in a router rather than building something from scratch.
If you are dead set on using VB6 you could make use of the winsock control. Here is a project using winsock to serve files. You could modify it to become a multithreaded proxy server instead. It will be a tough challenge though.
http://www.codeproject.com/KB/IP/winsock.aspx
Having some issues connecting to internet from an application where a customer is using a proxy server.
The following code seems to work most other customers, including those that use proxies.
Dim wc As New WebClient
wc.UseDefaultCredentials = True
wc.Proxy = WebRequest.DefaultWebProxy
wc.Proxy.Credentials = wc.Credentials
Dim responseBytes As Byte() = wc.DownloadData("http://www.google.co.uk")
Error is:
System.Net.WebException: The remote
server returned an error: (407) Proxy
Authentication Required.
Previously this same way of connecting did work using their old proxy server, now it doesn't work.
The customer has recently changed proxy server to one that uses NTLM authentication, so I guess this could be the issue.
Any ideas how I should be connecting any differently to above example?
Thanks,
Mike G