Port is a Published property in TIdFTP that indicates the port number to use when opening the control channel connection to the remote FTP server identifies in Host. 

Set values in the Host and Port properties prior to calling Connect. Values in the Username and Password properties are also required when AutoLogin contains True. 

Set the Port value in ProxySettings when a proxied connection to the remote server is required. 

The default value for the Port property is IDPORT_FTP, as assigned during initialization of the component.

AutoLogin 

Connect 

Login 

Host 

ProxySettings