def setVerifiedValue(self, row, field, value):
        """Sets the *value* for *field* in the parameter
        indexed by *row*, only if the value is within set limits

        :param row: the ith parameter number
        :type row: int
        :param field: detail of the parameter to set
        :type field: str
        :param value: pre-scaled value to assign to field
        """
        if self._parameters[row]['parameter'] == 'filename':
            return # cannot be set this way?
        if field == 'parameter':
            self.setParamValue(row, parameter=value)
        elif field in ['start', 'stop', 'step']:
            if self.checkLimits(row, value):
                kwd = {field : value}
                self.setParamValue(row, **kwd)