Timeout bei FTP-Synchronisation (WinSCP, PowerShell)

$Source = "c:\upload"  
$Destination = "/upload/"  

Add-Type -Path "WinSCPnet.dll"  

$sessionOptions = New-Object WinSCP.SessionOptions -Property @{
    Protocol = [WinSCP.Protocol]::Ftp
    HostName = "<HOST>"  
    PortNumber = <PORT>
    UserName = "<USER>"  
    Password = "<PASSWORD>"  
    <SECURITY OPTIONS>
    }

#$sessionOptions.AddRawSettings("PingType", "2") 
#$sessionOptions.AddRawSettings("PingIntervalSecs", "30") 

$session = New-Object WinSCP.Session

#$session.ReconnectTimeInMilliseconds = 10000

try {
    $session.Open($sessionOptions)
    $Session.SynchronizeDirectories([WinSCP.SynchronizationMode]::Remote, $Source, $Destination, $true, $true, [WinSCP.SynchronizationCriteria]::Either)
    } finally {
    $session.Dispose()
    }

"WinSCP.SessionRemoteException: Verbindung verloren.  
<SECURITY DETAILS>

Zeit abgelaufen (Kontrollverbindung)
Kopieren von Dateien auf den entfernten Rechner schlug fehl."