The TCP error codes were revised in a more recent version of the operating system. We have found that documentation in the 'Quick Help' section in some older devices did not get updated along with the code. The updated TCP connection status for Modbus TCP devices should be as follows:

5 = Connection failed, unable to bind (usually means remote device not connected or not reachable)
81 = Connection in progress (means unsuccessful connect attempt, still trying)
95 = Network is unreachable
97 = Connection aborted
98 = Connection reset by peer
103 = Connection timed out
104 = Connection refused
107 = Host is unreachable