Control.com - Nerds in Control

Hi,

We are executing a project using PCS7. In ES/OS & Server Machine, we are always getting the message "No Connection to Data Server". I tried to reset data of alarms & trends. Even the log files are ok. But I am always getting this message. Need some help plz.

Regards,
Anil

Hi Anil,

This sounds like an OPC connection problem.

Typical steps to diagnosing and correcting the cause:

1) Can you browse the OPC data server machine from the client

2) Is OPCEnum installed on the data server and secondly is it running (ideally as a service)

3) Ensure that windows authentication isn't the issue - firewalls set to off, user accounts are synchronised on both server and clients, use windows file sharing set to off, Data Execution Prevention set to Turn on DEP for essential windows programs and services only.

If still getting connection issues then move to DCOM settings

4) On the data server check the system wide DCOM settings:

I would expect:

Enabled DCOM+ to be checked
Default authentication Level to be Connect
Default Impersonation Level to be Identify

Default protocols to include Connection-Oriented TCP/IP

COM Security to include:

Default Security for Access Permissions of Everyone and System set to allow local and remote access for both accounts

Security Limits for Access Permissions of Anonymous LogOn and Everyone set to allow local and remote access for both accounts

Default Security for Launch and Activation Access Permissions of Administrators, Everyone, Interactive and System set to allow local and remote launch and local and remote activation for all accounts

Security Limits for Access Permissions of Administrator and Everyone set to allow local and remote launch and local and remote activation for both accounts

Reboot the data server for any DCOM settings to take effect.

5) There are other options available on the OPC Server specific DCOM settings, as well as who the OPC server service is running as, however before launching into these it is best to check vendor specifics on the settings.

Typically we have found the issues with some SCADA/DCS type packages to be that the account the OPC server runs under is not in the windows user group and needs to be added.

Regards,

Burnikell

Hi,

Although I have not got your system configuration... I mean ES/OS ES cannot be an OS. It can work as a client, and I believe the server machine is your main OS. If you can please explain your system it would be helpful. One most common case is I know that you will get this message when your client is in runtime and you shut down the OS (sever) or loose connection to it. In that case the client come up with message "no connection to data server". Anyway it would be helpful if you let us know about the system configuration and on which client or server you are getting this message.

shahiiee at yahoo. com