I seem to be having the same issue here. I am sending a HTTP request to a websever. If the server is offline, or destination IP incorrectly configured, there is about a 75 second delay before the Transmission Status frame - 0x89 is returned with an error.
I tried configuring different values for the following parameters:
Set or displays the timeout for connection on TCP client sockets. If 0, socket closes immediately after data sent.
Default = 0x64 (x100ms) = 100
So 10 seconds.
Set or read the timeout for a connection on a TCP server socket. The connection for this socket was initiated at the other end.
Default = 0x0258 (x100ms) = 600
So 60 seconds.
Unfortunately neither of these seemed to make any difference to anything I sent via Transmit (TX) Request: IPv4 - 0x20 when the destination endpoint is unavailable.
Did you have any more luck?