def checkUpdate(self, *args):
        """
        Updates values after first checking instrument parameters are OK.
        This is not integrated within update to prevent ifinite recursion
        since update gets called from ipars.
        """
        g = get_root(self).globals
        if not self.check():
            g.clog.warn('Current observing parameters are not valid.')
            return False

        if not g.ipars.check():
            g.clog.warn('Current instrument parameters are not valid.')
            return False
Updates values after first checking instrument parameters are OK.
        This is not integrated within update to prevent ifinite recursion
        since update gets called from ipars.