FCAI_PollWait: Specifying a wait time before POLL

To assist the application in managing POLL requests, the FTP client API automatically pauses before it reads from the pipe to the client process. This wait suspends the interface and the application and it protects the application from sending POLL requests at a rate that degrades performance.

FCAI_PollWait is used as follows:

The value 0 (the default setting) in FCAI_PollWait instructs a POLL request to wait 1 second prior to reading the pipe from the client.
A value greater than 0 enables a progressive wait timer and sets the maximum number of seconds that will be used. The field accepts a value in the range 0–255 seconds (4.25 minutes), but a value of 32 seconds or less is recommended for most subcommands.
The current timer value is stored internally in the interface and persists between POLL requests that are issued for the same prior subcommand. If a progressive timer has not been enabled, the current timer value is always 1 second. A progressive wait timer begins at 1 second and doubles after each POLL until the maximum setting is reached or exceeded. If exceeded, the timer value is set to the value that was supplied by the user.
The application can enable or disable the progressive timer and increase or decrease the maximum value to use on any POLL, regardless of the current timer value. The interface checks prior to each POLL to ensure that the timer does not exceed the specified maximum (the value 0 sets the maximum to 1 second).
The current timer value resets to 1 second after a POLL receives data from the pipe. This enables the user to retrieve all available output efficiently and removes much of the application's burden of managing a progressive timer. If a progressive timer has been requested, it begins to progress again as no data is returned (unless all output has been retrieved).
The application is responsible for sending each POLL request. POLL requests are not generated automatically by the interface. The PollWait interval is in addition to any wait done in the application program.