Message interface in synchronous mode but run in asynchronous

Question

I try to use SAP-XI in synchronous mode with JDBC to JDBC connection.
A 'Outbound' message Interface under synchronous mode is defined for
sender while an 'Inbound' message interface under synchronous mode is for
receiver.
In the sender communication channel, a "select" SQL statement is
placed for getting data via JDBC.
For inbound interface, a stored procedure is triggered and it will
return 2 paramaters.
From transaction SXMB_MONI, I found that the message was in 'asynchronous'
mode and I don't know how to collect the 2 output paramters.

Answer 1

Dear all,
Upon all your suggestions, my testing have a big jump with below results but still have some problem
In the sender communication channel, a "select" SQL statement is  placed for getting data via JDBC. It works.
For inbound interface (receiver), below stored procedure was actually triggered and it DOES return 2 paramaters.
<?xml version="1.0" encoding="UTF-8" ?>
<ns0:MT_t1 xmlns:ns0="http://xxx.xxx.hk/zxxxx/jdbc">
<update>
<storedProcedurename action="EXECUTE">
  <table>LIBRARY.PANSYTEST</table>
  <TRNX_TYPE IsInput="TRUE" TYPE="CHAR">001</TRNX_TYPE>
  <TRNX_NO IsInput="TRUE" TYPE="CHAR">101048</TRNX_NO>
  <OUT_TRNX_TYPE IsOutput="TRUE" TYPE="CHAR">001</OUT_TRNX_TYPE>
  <OUT_TRNX_NO IsOutput="TRUE" TYPE="CHAR">101048</OUT_TRNX_NO>
  </storedProcedurename>
  </update>
  </ns0:MT_t1>
  Then I got the response message from the inbound interface 
  <?xml version="1.0" encoding="utf-8" ?>
  <ns0:MT_t1_response xmlns:ns0="http://xxx.xxx.hk/zxxxx/jdbc">
  <update_response>
  <response_1>
    <update_count>0</update_count>
    </response_1>
    <OUT_TRNX_TYPE>001</OUT_TRNX_TYPE>
    <OUT_TRNX_NO>101048</OUT_TRNX_NO>
    </update_response>
  </ns0:MT_t1_response>
  This response message was mapped to below message type. I suppose this will be passed
  to outbound system (sender) and run a SQL "Update ps_cu_pg1iawd set cu_retrieved_by = "ZCU_CUSIS"
  cu_action_cd = 'P' where cu_trx_type = 001 and cu_trx_num = 101048"
  BUT the table ps_cu_pg1iawd is NOT updated and NO error was found in SXMB_MONI.
    <?xml version="1.0" encoding="UTF-8" ?>
  <ns0:MT_Response xmlns:ns0="http://xxx.xxx.hk/zxxxxx/jdbc">
  <statement>
  <PS_CU_PG1IAWD action="UPDATE">
    <table>ps_cu_pg1iawd</table>
  <access>
    <cu_retrieved_by>ZCU_CUSIS</cu_retrieved_by>
    <cu_action_cd>P</cu_action_cd>
    </access>
  <key_1>
    <cu_trx_type>001</cu_trx_type>
    </key_1>
  <key_2>
    <cu_trx_num>101048</cu_trx_num>
    </key_2>
    </PS_CU_PG1IAWD>
    </statement>
  </ns0:MT_Response>