I'm not really a networking person so sorry if this is overly simple, I'm just trying to troubleshoot an issue I've seen and trace the cause.
So I've got a PC talking to a PLC over a simple ethernet network interface. The problem I'm seeing is that occasionally response time is much slower every few requests (goes from 3ms to like 35ms). Traced it to this point and broke out wireshark and see that those long responses line up with the highlighted line, the TCP ack. 10.79 is the PLC, 10.71 is the PC.
Question: An ack like that, I'm assuming that means the receiving device (in this case the PLC) received the previous message (Job from PC) successfully? The seq number matches the ack number from the previous Job communication sent from the PC. The seq number of the following Ack_Data also matches.
Could that indicate some malformed response or problem in communication or is it more likely just the device (PLC) for some unknown reason took longer to send the Ack_Data back?
Thanks!
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