pingTest.ps1

param (
    [Parameter(Mandatory=$true)][string]$Hostname
)
$failure = ""
while (!$failure) {
  try {
   $net = [System.Net.Dns]::GetHostAddresses($Hostname)
   $Host.UI.RawUI.BackgroundColor = ($bckgrnd = 'DarkGreen')
  } catch [Exception] {
     $failure = "yes"
     $Host.UI.RawUI.BackgroundColor = ($bckgrnd = 'Red')
     return $_.Exception.Message
  }
  $ping = new-object system.net.networkinformation.ping
  $ping.send($Hostname)
  Start-Sleep -s 1
  Clear-Host
}

NB. may need to run 'Set-ExecutionPolicy Unrestricted' in an admin window