Configure Data-Ports for active FTP

In active FTP connection mode the data port for the connection to the FTP server is specified from the client and the server connects to this port. If the TwinCAT FTP Client is to be operated in active FTP mode, a port range can be defined from which a free port is to be used for establishing the connection.

The port range is set using the following three registry keys.

"HKEY_LOCAL_MACHINE\\Software\\Beckhoff\\TwinCAT FTP Client\\Configuration\ACTIVE_PortRangeEnabled"
"HKEY_LOCAL_MACHINE\\Software\\Beckhoff\\TwinCAT FTP Client\\Configuration\ACTIVE_MaxPort"
"HKEY_LOCAL_MACHINE\\Software\\Beckhoff\\TwinCAT FTP Client\\Configuration\ACTIVE_MinPort"

To enable the port range, the registry key "ACTIVE_PortRangeEnabled" must first be set to 1. Otherwise the TwinCAT FTP Client will use any free port to establish the connection.

The registry keys "ACTIVE_MaxPort" and "ACTIVE_MinPort" can be used to define the upper and lower limits of the port range, respectively.

To allow multiple simultaneous FTP connections, the port range must be selected accordingly. Example: If the TwinCAT FTP Client is to connect to three FTP servers simultaneously and start a file transfer via each connection, the port range must contain at least 3 ports.