Part Number: MSP432E401Y Hi, I'm testing the TCP/IP communication stability between MSP432 and a configuration SW running on PC. The configuration SW opens a TCP/IP session with the MSP432 based device and then sends MODBUS TCP requests, to which the MSP432 based device responds correctly. So far everything works as expected. The issue occurs when the communication channel is disturbed by electromagnetic interference. Electromagnetic interference causes sometimes a packet loss. A MODBUS TCP response sent from MSP432 is not received by configuration SW on PC, and the configuration SW sends the same request again. From now on we can see the issue: the MSP432 based device responds to the retransmission, but the configuration SW does not consider the response valid. Checking in the Wireshark logs, included, I noticed that the sequence number of the answer is not equal to the ACK number in the request. I guess this is why the answer is not considered valid. In the following requests by the configuration SW, the ACK number remains the same, whereas the sequence number of the response by the MSP432 keeps on incrementing. I attach the logs: PC IP address is 172.20.4.33, MSP432 IP address is 172.20.4.240. At time around 4.3 seconds, we can see that no response is received to query (message number 149) and retransmissions are issued. When a response is received from the MSP432 device (response message number 158), the sequence number of the response is not equal to the ACK of the request. I recompiled the TCP/IP stack, but I was not able to find a suitable fix. Do you think the analysis is correct, or maybe the configuration SW is not behaving correctly when sending the retransmissions? Thanks (Please visit the site to view this file)
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