Dcom

Why is DCOM such a struggle, I am trying to set up windows 7 OPC DA Server to be used as a client for an Edge Server so we can then use OPC UA/MQTT to broadcast across the Vlans / Firewalls etc.

I seem to be going around in circles, I can get DCOM to allow OPC Explorer from to see the OPC Server from another machine, yet when I try Cogent DataHub as the Client, it is blocked. In Wireshark is showing that it is not impersonating the OPC Server/OPC account but instead using the Localmachine\Administrator. Which of course is not allows

Everything is in the same workgroup and on the same Lan. Everything is set to allow impersonation and allow anonymous etc. :Ahhhhhhh:

We want to run the Data hub on a separate machine as the Server is already busy with OPC DA and the rest of the processes.

Client Machine (DataHub) Windows 10 (Beckhoff)
Server Machine (Windows 7) with Wonderware FSGateway.

I know I can tunnel using DataHub, but this would involve more licenses.. so more £££.

Does anyone have FAIL PROOF Dcom setup guide they could link?

DCOM is end of life. Microsoft will stop it from operating in a year. If you have the latest Windows updates installed it turns off DCOM and you have to go into the registry to turn it back on. June of next year you will not be able to turn it on.
Maybe find a no-Dcom communication method.
With DCOM you have to have the same user on both machines with the same password and you have run the services under the user name.
Go to OPC Training Institute and look for OPC & DC)M Troubleshooting: Quick Start Guide

If OPC-UA is an option for you, use it. OPC-DA is made of pain and suffering.

doctord said:

DCOM is end of life. Microsoft will stop it from operating in a year. If you have the latest Windows updates installed it turns off DCOM and you have to go into the registry to turn it back on. June of next year you will not be able to turn it on.
Maybe find a no-Dcom communication method.
With DCOM you have to have the same user on both machines with the same password and you have run the services under the user name.
Go to OPC Training Institute and look for OPC & DC)M Troubleshooting: Quick Start Guide

Click to expand...

So if DCOM is obsolete as of March 2023... Does that mean OPC DA is dead?

I assume the best practice is keeping DA internal to a single machine and using other protocols for intermachine communications?

Most of the kit I am working with is Windows 7 or older, although our Gateway Machines (Edge Machines( are Windows 10 LTS, so I assume as our IT & Micorosft force patching then in March 2023, we're "Screwed"

That they still let you use windows 7 is amazing.
https://www.google.com/search?q=windows+7+end+of+life

you are right on the same machine you do not need DCOM to go from OPC DA to another protocol. Already if you have a patched machine there is a registry value that needs to be changed to allow DCOM across the network, So I will not build a new system using OPC DA across the network and convert to another protocol for network comms.

mad4x4 said:

So if DCOM is obsolete as of March 2023... Does that mean OPC DA is dead?

I assume the best practice is keeping DA internal to a single machine and using other protocols for intermachine communications?

Most of the kit I am working with is Windows 7 or older, although our Gateway Machines (Edge Machines( are Windows 10 LTS, so I assume as our IT & Micorosft force patching then in March 2023, we're "Screwed"

Click to expand...

Off-node OPC DA will not work once that patch comes unless the client and server both have been updated to meet the new security requirements. If you require off-node OPC DA, you better be communicating with all the involved vendors to see how they are fixing this.

On-node OPC DA is not affected.

OPC UA and MQTT are the future. No DCOM, encryptable, etc. Many hardware vendors are now even embedding these into the devices.

I suspect that eventually this will meet the same fate as NETDDE (yes, I'm an old-timer).

OK, so have had a think about this and the fact that we have Cogent Datahub. What I'm going to do is run a copy of Cogent on the OPC Server and use this to OPCDA ->OPCUA then my other copy of Cogent will be the edge Server Gathering data from ODBC, OPCUA(DA) etc. and encoding and moving it over to the MQTT & Client for Had off at the Edge on Network.

A bit more costly as I now need an extra Cogent License, but I can get away with a DHGAT at £885 rather than using another IOTGAT at £3K., and it took about 30mins to set up this morning.

There are many DCOM guides out there, I have them all and none of them work all the time. It's called DCOM HELL for a reason.

Today, I wouldn't not use DCOM at all unless there are simply no other way.

harryting said:

Today, I wouldn't not use DCOM at all unless there are simply no other way.

Click to expand...

Mind that double negative