topic Re: KEPServerEX OPC UA Client Driver Unable to Connect to CIMON OPC UA Server in Kepware

KEPServerEX OPC UA Client Driver Unable to Connect to CIMON OPC UA Server

uvcssb — Thu, 28 Nov 2024 09:31:58 GMT

1. Current Situation

CIMON OPC UA Server Information:

IP: [CIMON OPC UA Server IP]
Port: [CIMON OPC UA Server Port]
Network: Same local network (Ping test and TCP connection successfully confirmed).

KEPServerEX Status:

The OPC UA Client Driver in KEPServerEX cannot detect the CIMON OPC UA Server during server discovery.
Even when the Endpoint URL is manually entered, the connection fails.

Other Client Status:

UaExpert:
- Successfully connects to opc.tcp://[CIMON OPC UA Server IP]:[CIMON OPC UA Server Port] (with Security Policy: None, Message Security Mode: None).
- Node browsing and data reading from the CIMON OPC UA server work perfectly.
Node.js (node-opcua library):
- Successfully connects to the same Endpoint URL and reads data successfully (with Security Policy: None, Message Security Mode: None).

2. Troubleshooting Attempts

Network Connection Check:

From the machine running KEPServerEX ([KEPServerEX Machine IP]):
- Ping to [CIMON OPC UA Server IP] → Successful response.
- Test-NetConnection [CIMON OPC UA Server IP] -Port [CIMON OPC UA Server Port] → TCP response successful.
No network connection issues detected between KEPServerEX and CIMON OPC UA Server.

Firewall Configuration:

Allowed TCP Port [CIMON OPC UA Server Port] on the machine running KEPServerEX ([KEPServerEX Machine IP]).
Configured both inbound and outbound rules.

Security and Authentication:

Configured KEPServerEX with Security Policy: None and Message Security Mode: None to match the CIMON OPC UA Server.

3. Main Issue

The issue does not appear to be related to network connectivity or security/authentication configurations.

While other clients (UaExpert, Node.js-based clients) successfully connect to the CIMON OPC UA Server, only KEPServerEX fails to discover or connect to the server.

4. Environment Details

KEPServerEX Version: v6.17.240.0
Machine Running KEPServerEX:
- IP: [KEPServerEX Machine IP]
CIMON OPC UA Server:
- IP: [CIMON OPC UA Server IP]
- Port: [CIMON OPC UA Server Port]
- Security Settings: Security Policy None, Message Security Mode None
Network Environment: Same local network, TCP Port [CIMON OPC UA Server Port] allowed through the firewall.

Re: KEPServerEX OPC UA Client Driver Unable to Connect to CIMON OPC UA Server

rajskumar — Thu, 28 Nov 2024 11:58:35 GMT

Hello, Thank you for the detailed description.

Are you encountering any errors while browsing the CIMON OPC UA Server (in manual connection)? Please verify the client-side configuration using the article below.

https://www.ptc.com/en/support/article/CS298913

If you are prompted to log in to view the complete article, you can use your MyKepware login credentials.

Additionally, I suggest capturing Wireshark packets to identify the issue.

Re: KEPServerEX OPC UA Client Driver Unable to Connect to CIMON OPC UA Server

uvcssb — Fri, 29 Nov 2024 03:07:29 GMT

Current Situation

CIMON OPC UA Server Details
- IP: [CIMON_IP]
- Port: 4840
- Security Policy: None
- Message Security Mode: None
UaExpert Connection
- Successfully connects to the CIMON OPC UA Server, allowing node browsing and data reading.
Node.js Connection
- Successfully connects to the CIMON OPC UA Server, enabling data read/write operations.
KEPServerEX Connection
- Using the OPC UA Client Driver, attempting to connect to the CIMON OPC UA Server results in a BadTcpMessageTooLarge error.
- Wireshark packet analysis shows that after sending a GetEndpointsRequest, the CIMON OPC UA Server returns this error.

Wireshark Request Packet Comparison

UaExpert Request Packet:
- Message Size: 98 bytes
- Details:
  - EndpointUrl: opc.tcp://[CIMON_IP]:4840
  - LocaleIds: None (ArraySize: 0)
  - ProfileUris: None (ArraySize: 0)
KEPServerEX Request Packet:
- Message Size: 167 bytes
- Details:
  - EndpointUrl: opc.tcp://[CIMON_IP]:4840
  - LocaleIds: None (ArraySize: 0)
  - ProfileUris: 1 URI included (http://opcfoundation.org/UA-Profile/Transport/uatcp-uasc-uabinary)
TCP Segments Comparison:
- UaExpert Request: Sent in a single TCP segment.
- KEPServerEX Request:
  - Reassembled TCP Segments:
    - Frame #101: 12 bytes
    - Frame #102: 4 bytes
    - Frame #103: 151 bytes
  - Total Length: 167 bytes
- It seems the CIMON OPC UA Server might have trouble handling segmented TCP packets from KEPServerEX.
Comparison Results:
- KEPServerEX’s request is slightly larger due to the inclusion of ProfileUris.
- However, 167 bytes is not typically considered a "large message" in OPC UA communications.
- UaExpert successfully handles requests larger than 167 bytes without issues.

Steps Taken to Resolve

Network Connection
- Ping and TCP connection tests confirm accessibility (Port 4840).
KEPServerEX Configuration
- Configured with Security Policy: None, Message Security Mode: None.
Wireshark Analysis
- Compared request message size and TCP segments between UaExpert and KEPServerEX.
- KEPServerEX’s request is sent in multiple TCP segments, which might not be properly handled by the CIMON OPC UA Server.

Re: KEPServerEX OPC UA Client Driver Unable to Connect to CIMON OPC UA Server

uvcssb — Fri, 29 Nov 2024 03:32:13 GMT

Current Situation

CIMON OPC UA Server Details

IP: [CIMON_IP]
Port: 4840
Security Policy: None
Message Security Mode: None

UaExpert Connection

Successfully connects to the CIMON OPC UA Server, allowing node browsing and data reading.

Node.js Connection

Successfully connects to the CIMON OPC UA Server, enabling data read/write operations.

KEPServerEX Connection

Using the OPC UA Client Driver, attempting to connect to the CIMON OPC UA Server results in a BadTcpMessageTooLarge error.
Wireshark packet analysis shows that after sending a GetEndpointsRequest, the CIMON OPC UA Server returns this error.

Wireshark Request Packet Comparison

UaExpert Request Packet:

Message Size: 98 bytes
Details:
- EndpointUrl: opc.tcp://[CIMON_IP]:4840
- LocaleIds: None (ArraySize: 0)
- ProfileUris: None (ArraySize: 0)

KEPServerEX Request Packet:

Message Size: 167 bytes
Details:
- EndpointUrl: opc.tcp://[CIMON_IP]:4840
- LocaleIds: None (ArraySize: 0)
- ProfileUris: 1 URI included (http://opcfoundation.org/UA-Profile/Transport/uatcp-uasc-uabinary)

TCP Segments Comparison:

UaExpert Request: Sent in a single TCP segment.
KEPServerEX Request:
- Reassembled TCP Segments:
  - Frame #101: 12 bytes
  - Frame #102: 4 bytes
  - Frame #103: 151 bytes
- Total Length: 167 bytes
It seems the CIMON OPC UA Server might have trouble handling segmented TCP packets from KEPServerEX.

Comparison Results

KEPServerEX’s request is slightly larger due to the inclusion of ProfileUris.
However, 167 bytes is not typically considered a "large message" in OPC UA communications.
UaExpert successfully handles requests larger than 167 bytes without issues.

Steps Taken to Resolve

Network Connection

Ping and TCP connection tests confirm accessibility (Port 4840).

KEPServerEX Configuration

Configured with Security Policy: None, Message Security Mode: None.

Wireshark Analysis

Compared request message size and TCP segments between UaExpert and KEPServerEX.
KEPServerEX’s request is sent in multiple TCP segments, which might not be properly handled by the CIMON OPC UA Server.