Powershell error trapping - powershell

Question

I've got a script that does some server maintenance. Part of the job is to stop and restart services on the host server. The easiest way to tell when the service is fully back online again is attempt to connect to the admin port. Once you're able to connect to the admin port, than the service is up and ready for business. Simple enough. This bit of code will loop until it's back online:
function test-port {
$PortProbe = New-Object Net.Sockets.TcpClient
$ErrorActionPreference = "SilentlyContinue"
while ($PortProbe.Connected -eq 0){
$PortProbe.Connect("localhost",3041)
write-host "Server is off line... waiting for it to come online."
sleep 1
}
write-host "Server is back online!"
$ErrorActionPreference = "Continue"
$PortProbe.Close()
}
test-port
So in my script I do my work, restart services and then call "test-port" to have the script to wait for the service to come back online before proceeding.
The problem I'm running into is if I have a generic trap in the script, it's trapping the connection error when the port isn't ready yet.
Exception calling "Connect" with "2" argument(s): "No connection could be made because the target machine actively refused it 127.0.0.1:3041"
At line:6 char:27
+ $PortProbe.Connect <<<< ("localhost",3041)
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
I've got a trap statement at the end in case some really bizarre error happens, it'll kick off an e-mail alert. But it breaks the functionality of the test-port function.
In theory, I could trap this specific TCP/IP connection error and tell it to just continue on like nothing had happened, but I can't figure out how to tell what the class of the error message is. I thought it would be something like this:
trap [Net.Sockets.TcpClient] { #Don't Panic
}
But that's not right.
Any suggestions? Do I need to handle this completely differently?

Answer 1

Rather than dropping to sockets, why not use the Get-Service cmdlet in a loop to check the service's status e.g.:
do {
$svc = Get-Service -ComputerName Localhost w3svc
$connected = $false
if ($svc -and $svc.Status -eq 'Running') {
$connected = $true
}
Start-Sleep -Milliseconds 500
} while (!$connected)