How to register an event in Powershell so it stays permanent? - powershell

Question

I have the below script, that is just supposed to monitor a folder, and when a .xlsx file is created, then it should convert it to a .csv file in another folder. It works on the first file created, but it doesn't work on the next file being created in the folder. How can I get the event to stay permanent?
$ErrorActionPreference = 'Stop'
$folder = 'c:\Users\exgtcl\hotfolder'
$destination = 'c:\Users\exgtcl\targetfolder'
$filter = '*.xlsx'
Function Convert-Csv
{
[CmdletBinding()]
Param
(
[Parameter(Mandatory=$true)][String]$FullPath
)
$ExcelFiles = Get-ChildItem $FullPath
Write-Host "Working on file '$FullPath' "
$excelApp = New-Object -ComObject Excel.Application
$excelApp.DisplayAlerts = $false
$excelApp.Visible = $false
$workbook = $excelApp.Workbooks.Open($ExcelFiles.FullName)
$newName = "$destination\output.csv"
$workbook.SaveAs($newName, [Microsoft.Office.Interop.Excel.XlFileFormat]::xlCSV)
$workbook.Close()
# Release Excel Com Object resource
$excelApp.Workbooks.Close()
Start-Sleep 2
$excelApp.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($excelApp) | Out-Null
}
$fsw = New-Object IO.FileSystemWatcher $folder, $filter -Property #{
IncludeSubdirectories = $false
NotifyFilter = [IO.NotifyFilters]'FileName, LastWrite'
}
$action = {
$path = $Event.SourceEventArgs.FullPath
$name = $Event.SourceEventArgs.Name
$changeType = $Event.SourceEventArgs.ChangeType
$timeStamp = $Event.TimeGenerated
Convert-Csv -FullPath $path
Start-Sleep 3
Write-Host "moving files"
Move-Item $path -Destination $destination -Force -Verbose
}
$onCreated = Register-ObjectEvent $fsw Created -SourceIdentifier FileCreated -Action $action