Exception for "The specified network name is no longer available"

[kva]

The common part of my script is

def connect():
    global nr
    for i in range(60):
        if not tab.Session.Connected:
            try:
                tab.Session.Connect()
                nr = tab.Screen.WaitForStrings('#', 20)
                break
            except ScriptError:
                pass
        else:
            nr = True
            break
    else:
        return False
    return nr

def main():
    global nr
    sending, waitingforstring, etc

tab = crt.GetScriptTab()
tab.Screen.Synchronous = True
tab.Screen.IgnoreEscape = True

if connect():
    main()

Sometimes when script tries to connect to unavailable device, the pop-up window tells me: "The specified network name is no longer available". ScriptError does not handle this error? Which exception should?