Thank you - yes I will be troubleshooting with DCOM once the device is available.

Unfortunately it is now offline until the new year for year-end maintenance.

Thank you for your assistance.

Thank you for the answers, although they're not quite what I had hoped for.

Notes:

1./2. BrowseTree was just one thing I tried. I tried all possible combinations of it, BrowseNodes, BrowseBranches, and BrowseLeaves. I just didn't include everything for simplicity.

Questions:

1. This does not work. This is pretty much what I started with, and then moved on to other calls when it didn't work. It just returns and empty list of nodes when called on the root node.

2. This is a Sartorius OPC Server.Net system that is then connected to several Sartorious B-DCU systems.


With all that, I believe I have figured out the issue. My OPC-DA client code runs as part of AWS Greengrass, and was running as a local user created and used by Greengrass. When I tested the code using the an Admin user, the code works and I can browse nodes. So I can work to adjust users and permissions on the machine to make this work.

What is somewhat frustrating is this just failed to return any information about an error or throw an Exception.

Thank you - I apologize for the two posts. I thought the other one had failed to post - I missed the moderation message before navigating away.

I am attempting to browse and item tree starting from the root node. This is code that works
correctly with three other OPC-DA servers, but it not working correctly with one. Other clients
(e.g. the Softing OPC Demo Client) can connect to the server and display nodes. The server claims to support OPC-DA 3.0.

My code looks like this (some minor details left out).

import opclabs_quickopc

...

client = EasyDAClient()
servers = IEasyDAClientExtension.BrowseServers(client)

for server in servers:
sd = ServerDescriptor(server)
results = IEasyDAClientExtension2.BrowseTree(client, sd)
print(results)

for server in servers:
branches = IEasyDAClientExtension.BrowseBranches(client, "", server.ServerClass)
for branch in branches:
print(branch)


Neither results or branches contains any data.

I have several questions to help me attempt to troubleshoot this further.

1. How can I enable detailed logging for the Python wrapper code and the underlying OpcLabs .NET
objects?

2. Is there any way through the Python code that I can modify the enum tagOPCNAMESPACETYPE used in
function calls? I would like to try settin OPC_NS_HIERARCHIAL and OPC_NS_FLAT to see if the
behavior differs.

3. Is there any way I can access the OPC-DA groups functionality from version 2 from Python? I
would like to see if that is an option.