Refer to the Client Application Switchover section in this topic.
View the License – FAQ for quick resolution to common license issues.
Remote OAS Service Access
The OAS Service must be started to be accessed by a local or remote OPC client component or application. Use the OAS Service Control application to Start the Service.
If you are using a Firewall make sure to open up TCP port 58724 for both inbound and outbound traffic.
You can check if the TCP port is open using the Windows Command Prompt with the following command on the same computer as the OAS Service.
If the service is not started or the port is not open then the command will just return without any results.
To check a remote computer port use PortQry from Microsoft.
Open PortQryV2.exe to install PortQry.
Use the Windows Command Prompt from the PortQryV2 directory with the following command. Replace opcsystems.com with your own IP address of your server.
You can adjust the TCP Port number used for the Service under Configure-Options-Networking.
If you change the default port number from 58724 make sure to also adjust each remote service accessing this service under Configure-Options-Remote Services and in each .NET application assembly using the WCFPortNumber property.
Adjustable WCF Port Number
How to adjust WCF port number in the realtime service and all client applications.
The best way to network to remote OPC Servers is to install the OAS Service on the remote PCs where the OPC Server is running and use the built in network features of Open Automation Software that use WCF.
How to network all products to central service using a fixed IP Address or registered domain name for the Internet.
If you decide you still want to use remote DCOM to connect to remote OPC Servers edit the file NetworkNodes.txt in C:Program Files (x86)Open Automation SoftwareOPC Systems.NET.
Connecting to Data Access OPC Servers is best implemented when the OAS Service is installed where the OPC Servers you are connecting to are. View Remote OAS Service Access on how to enable easy remote networking from the client applications to a service without using remote DCOM.
If you are having trouble connecting to a local or remote OPC Server try setting the Service Logon to a proper local User Account or use the OPC Data Fix which can be enabled using the OAS Service tray application.
If you can obtain data from one OPC Client, but not other OPC Clients at the same time verify that the OPC Server identity is set to Interactive User in the DCOM Configurator. View the steps listed below.
If you are using the OPTO 22 OPC Server you will need to do this step after installing their OPC Server.
Start the DCOM configurator by selecting run and type DCOMCNFG and select OK.
Select Component Services, Computers, My Computer, and DCOM Config.
Select the OPC Server you are connecting to in the right window and right click to select Properties.
Select the Identity tab and select the option “The interactive user.”
Restart the system and verify using the Task Manager under Processes that only one instance of the OPC Server runs with multiple clients connected to it.
If both Open Automation Software and the OPC Foundation Sample Client are unable to access data from OPC Servers and the OPC Foundation Core components are installed use the following section to setup the DCOM Security of the operating system.
If it is not possible to edit limits in DCOM (buttons Edit Limits grayed, not like below):
With regedit delete the 2 restrictions MachineAccessRestriction and MachineLaunchRestriction, in HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows NTDCOM
System Wide Configuration
dcomcnfg => System wide configuration
My Computer => Properties
Access Permissions => Click Edit Default
Access Permissions => Click Edit Limits
Performance… and Distribute COM… same settings as ANONYMOUS
Launch and Activation Permissions => Click Edit Default…
Launch and Activation Permissions => Click Edit Limits…
Performance… and Distributed COM… same settings as INTERACTIVE
SYSTEM WIDE CONFIGURATION => ADD A USER IN COM security
If it is necessary to add a user click Add…
Click Find Now
COM APPLICATION WIDE CONFIGURATION
OPC enum service DCOM configuration