When you start the FTP Client with a startup command that executes a script file, you can include a command line switch that directs the client to create a log file that stores a record of the results of the commands that are executed.
If you want to create a log file when you execute a script file from within the client application, from the Tools menu, choose Start Logging, and then, from the Script menu, choose Run Script.
If you are using the FTP Automation API to control the FTP Client application, you can control logging using the StartLog and StopLog methods.