LabVIEW学习乐园

由于OPC采用了DCOM技术，因此Windows的权限限制经常会导致OPC Server在网络上无法连接。下面是我不断摸索出来的DCOM配置方法，基本上是屡试不爽:D

      由于我的两台机子都同时用作server 和 client，所以两台机子的配置完全一样，以下的配置是最宽松的条件，基本上能满足所有类型的OPC server.

Winxp Sp2

 1.关闭Sp2防火墙

 2.add system administrator user :OPCUser, pass: 123456

 3.确保安装了OPCEnum

 3.Control panel->Administrator tools->local security policy->local policies->security options->Network access: sharing and security model for local accounts
Change this setting to :"classic-users authenticate as themselves".

 4.Run dcomcnfg

 5.(Menu start-> Run-> dcomcnfg,  choose Component Services-> Computers -> MyComputer -> Properties)

o        do click on the "Default Properties" tab 

The Enable Distributed COM on    this computer MUST be  checked.

The Default Authentication Level should be set to Connect.

The Default Impersonation Level should be set to Identity

o        do click on the "Default COM Security"

      click Edit Limits->add these users:OPCUser, INTERACTIVE, NETWORK, everyone, ANONYMOUS LOGON, SYSTEM. Set every user with all permissions.

      add these users to all the other Edit Default and Edit limits

 6.Expand DCOM Config, set OPCEnum.

• Authentication Level should be set to Connect.
• Set all Security items to Customize
• click Edit ->add these users:OPCUser, INTERACTIVE, NETWORK, everyone, ANONYMOUS LOGON, SYSTEM. Set every user with all permissions.

• In the Identity tab select "the system account

   7.For specified OPC Server, maybe you need do some configuration on that server...

   8. Restart Computer.

   9. acess the server  computer in network neighbor with the user "opcuser".

   10.Try to access the OPC server in remote client

Good luck!

遇到过的问题：

• 看不到OPC server
• 不能连接
• WieNer的VME OPC Server在local 机器上SyncIO和AsyncIO都可以，在远程机器上只能通过Server explorer的SyncIO读写，labview8无论sync还是Async都无法读写
  • set Kvaser OPC Server ->Identity as "The interactive uSer"
  • Because the asynchronous mode used callback, so you must set the client's dcomcnfg to be same as server side.
  • Control Panel->Administrative Tools->Services->National Instruments Variable Engine->Log on, log on as "opcuser"
• 能连接不能看到OPC tag

参考文献：

OPC and DCOM: 5 things you need to know

OPC& DCOMTroubleshooting: Quick Start Guide