Each Ethernet TCP/IP device that communicates with a SIXNET station or I/O module will initiate a TCP/IP session. EtherTRAK modules allow up to two TCP/IP sessions at any given time. Gateways and RTUs allow up to four TCP/IP sessions by default, and can be configured to allow additional TCP/IP sessions, depending on available memory. IPm stations support many TCP sessions. If all available TCP/IP sessions are in use and another Ethernet TCP/IP device needs to communicate, it will be unable to do so until:
One of the existing TCP/IP sessions is terminated by the Ethernet device that started it
Or
One of the existing TCP/IP sessions is terminated by the station or I/O module when a TCP/IP session goes inactive for a user-selectable period of time.
The maximum allowable number of TCP/IP sessions for a SIXNET station can be defined from within the Resources window of the SIXNET I/O Tool Kit program. The TCP/IP Timeout can be defined from within the Ethernet Main Port Setup window.