The library provides a global Modbus TCP connection manager which manages the connections to the Modbus TCP servers used by the different Modbus TCP client function blocks.
The global Modbus TCP connection manager is capable to manage up to 16 TCP connections to different Modbus TCP servers and up to 16 requests per TCP connection at the same time.
If a client function block attempts to open a new connection while the maximum number of connections is already established, the longest inactive connection is closed and the new connection is established. In general, connections that are inactive for 40 seconds are closed by the client.
The global instance GVL.G_ifConnectionManager allows you to obtain the status of the Modbus TCP connection manager.