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uvcssb4-Participant
4-Participant
November 28, 2024
Solved

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

  • November 28, 2024
  • 1 reply
  • 1188 views

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.
Best answer by rajskumar

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.

1 reply

R
rajskumar16-PearlAnswer
16-Pearl
November 28, 2024

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.

U
uvcssb4-ParticipantAuthor
4-Participant
November 29, 2024

Current Situation

  1. CIMON OPC UA Server Details

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

  2. UaExpert Connection

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

  3. Node.js Connection

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

  4. 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

  1. UaExpert Request Packet:

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

  2. KEPServerEX Request Packet:

  3. 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.

  4. 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

  1. Network Connection

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

  2. KEPServerEX Configuration

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

  3. 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.
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