$subnet = "192.168.1"
1..254 | ForEach-Object {
    $ip = "$subnet.$_"
    try {
        $result = Test-Connection -ComputerName $ip -Count 1 -ErrorAction Stop
        Write-Output "$ip - Responded in $($result.ResponseTime) ms"
    } catch {
        Write-Output "$ip - No response"
    }
}