==== XML ====
<code xml>
    <function name="rpcf_link_user_tariff" id="0x3018">
      <input>
        <integer name="user_id"/>
        <integer name="account_id" default="0"/>
        <integer name="tariff_current"/>
        <integer name="tariff_next" default="tariff_current"/>
        <integer name="discount_period_id"/>
        <integer name="tariff_link_id" default="0"/>
      </input>
      <output>
        <integer name="tariff_link_id"/>
        <if variable="tariff_link_id" value="0" condition="eq">
          <error code="13" comment="unable to link user tariff"/>
        </if>
      </output>
    </function>
</code>
==== PHP ====
<code php>
	function rpcf_link_user_tariff($user_id,$account_id=0,$tariff_current,$tariff_next=$tariff_current,$discount_period_id,$tariff_link_id=0) { //0x3018
		$ret=array();
		if (!$this->connection->urfa_call(0x3018)) {
			print "Error calling function ". __FUNCTION__ ."\n";
			return FALSE;
		}
		$packet = $this->connection->getPacket();
		$packet->DataSetInt($user_id);
		$packet->DataSetInt($account_id);
		$packet->DataSetInt($tariff_current);
		$packet->DataSetInt($tariff_next);
		$packet->DataSetInt($discount_period_id);
		$packet->DataSetInt($tariff_link_id);
		$this->connection->urfa_send_param($packet);
		if ($x = $this->connection->urfa_get_data()) {
			$ret['tariff_link_id']=$x->DataGetInt();
//			$this->connection->urfa_get_data();
		}
		return $ret;
	}
</code>