Does a router tells a slave device to close a TCP connection, if the router loses connect from the master device ? So, I have a Qterm-g72 HMI and I am trying to connect it to a Moxa over TCP Modbus. This only works if a Computer or a router is between the Moxa and the HMI. I am trying to found out why. So, my question is does a computer or a router close the connection to the Moxa if it lose it from the HMI ? The HMI is the master so it does the talking and the Moxa is the slave. The Moxa does not know to lost the connection if the HMI does not tell is to close with TCP, so I wanted to know if the Computer or Router would do that ? Also does anyone else think they might know why the HMI and the Moxa will not work with a router or a computer in between?