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TcpSocketServer (Script v2)

The TcpServer object allows Q-SYS cores to accept client TCP/IP connections from devices on the network. The TcpSocketServer is different from the TcpSocket library because of the inbound/waiting nature of a TCP Server. TcpSocket generally allows Q-SYS to establish outgoing TCP client sessions to remote TCP Servers. The TcpSocketServer library enables a script to create a TCP "listener" on a specific TCP port. This listener isn't the individual TCP socket itself–it "emits" a unique TcpSocket instance whenever a remote TCP client connects to the listen port. Thus, the TcpSocketServer instance's EventHandler is where the specific incoming TCP socket connection is granted a unique socket instance(the argument of the TcpSocketServer's EventHandler function). The EventHandler target function for this new socket instance will be defined as an anonymous function or (more likely) as a reference to a separate socket event handling function. It is important to note that if multiple incoming socket connections are made, a separate socket instance (and EventHandler) are created by the Lua runtime engine for each connection and all socket transactions are handled by each socket connection's separate EventHandler instances (which are assigned only as necessary).

New()

Purpose:    Static class method. Creates a new instance of the TcpServer class.

Response:   server

Type: TcpServer

Definition: The newly created server

Listen( )

Purpose:    Opens the TcpServer on specified TCP port on all network interfaces

Parameter: port

Type: integer

Definition: The port to use for listening for connections

Response:   error

Type: string

Definition: nil if open succeeded, otherwise a string representing the error

Close()

Purpose:    Closes the TcpServer

Example

Note that in the following example, the EventHandler arguments and function names were chosen to assist in understanding what is happening when a TCP socket connection occurs. These names are not special and can be changed in your own scripts. But simply calling everything 'sock' throughout can be confusing when learning the concept.