Troubleshooting Ethernet Connectivity Issues in MODBUS-TCP Enabled Devices

Our device has an Ethernet PHY (LAN8720) connected to the LPC1768 microcontroller via an RMII interface and the device connected to the PLC using the MODBUS-TCP protocol.

However, after running this protocol for a couple of days, we noticed that the device would sometimes lose connection with the PLC.

When we tried to diagnose the problem, we found that the device wouldn't respond to ping commands, but everything else seemed to be working fine. Oddly, restarting the device fixed the issue temporarily.

Now, we're trying to figure out if the problem lies with the software that manages the Ethernet connection or if there's an issue with the hardware. We're looking into the versions of the drivers and middleware we're using to see if they might be causing the problem.

We have following driver and middleware version
Ethernet PHY (LAN8720) driver version :- V6.2.0
Network Protocol Version :- 7.14.0
CMSIS RTOS version :- 1.1.0

  • Check the operation of the network stack. If the system gets stuck in the net_sys_error function, it is usually a critical error in the network stack. A restart is usually required to recover. Such a situation can be caused by problems in the application that can corrupt the memory. If this is not the case, you should look for hardware errors. Perhaps some kind of watchdog reset should be built into the application.