TCP Communication Issues on Speedgoat with MATLAB R2022 and Later

Hi,

I’m facing an issue with TCP communication on a Speedgoat target when using MATLAB versions R2022 and later. The exact same Simulink model and configuration work perfectly in R2021b, but starting from R2022 onwards, the TCP client fails to connect to the PLC server at all.

MathWorks Support has confirmed that there were no changes made to the TCP stack itself. However, in R2022 and newer releases, the target file has changed from slrealtime.tlc to speedgoat.tlc, and this modification may be affecting how TCP communication is handled on the Speedgoat system.

In R2021b, the same setup connects and exchanges data reliably, but in later releases, the TCP connection simply does not establish.

Has anyone else encountered this issue on Speedgoat targets after upgrading beyond R2021b?

Any insights into what might have changed in the target configuration or how to restore the previous TCP behavior would be very helpful.

Thanks in advance for your assistance and suggestions.

Best regards,

Faisal

Answer 1

[Satyam]

Hi @Faisal Aftab,

To help isolate the problem, please try the following checks:

• Check for Warnings/Errors: Open the Target Computer Status Monitor in Simulink Real-Time and review any warnings or errors reported.
• Test PLC Connectivity: Connect to the PLC from a different client (e.g., another PC) to confirm the PLC is accepting connections. If this works, the PLC is likely fine.
• Test Speedgoat with a Different Server: Try connecting the Speedgoat to a different TCP server, such as the host machine using MATLAB’s tcpserver function. This helps confirm whether the issue is with the Speedgoat or the PLC.tcpserver Documentation
• Run the Application Without Host Connection: Disconnect the host from the target before starting the real-time application. Use SSH to access the Speedgoat and start the application via the Target Computer Command-Line Interface.You can refer to this Target CLI documentation: https://www.mathworks.com/help/slrealtime/tcp.html
• Monitor Network Traffic: Use a network monitoring tool to inspect traffic between Speedgoat and the PLC. Speedgoat includes tcpdump for packet capture. Alternatively, use Wireshark on a PC in the network. If neither Speedgoat nor PLC can run Wireshark, set up a network topology that allows packet monitoring.Wireshark Capture Setup Guide.