Unable to capture the parameter values from a PL/SQL procedure

Question

hi.
i'm trying to capture the parameter values of a PL/SQL procedure by calling inside a anonymous block but i'm getting a "reference to uninitialized collection error" ORA-06531.
Please help me regarding.
i'm using following block for calling the procedure.
declare
err_cd varchar2(1000);
err_txt VARCHAR2(5000);
no_of_recs number;
out_sign_tab search_sign_tab_type:=search_sign_tab_type(search_sign_type(NULL,NULL,NULL,NULL,NULL));
cntr_var number:=0;
begin
     rt843pq('DWS','3000552485',out_sign_tab,no_of_recs,err_cd,err_txt);
     dbms_output.put_line('The error is ' ||err_cd);
     dbms_output.put_line('The error is ' ||err_txt);
     dbms_output.put_line('The cntr is ' ||cntr_var);
     for incr in 1 .. OUT_SIGN_TAB.count
     loop
     cntr_var := cntr_var + 1 ;
Dbms_output.put_line(OUT_SIGN_TAB(incr).ref_no||','||OUT_SIGN_TAB(incr).ciref_no||','||OUT_SIGN_TAB(incr).ac_no||','||OUT_SIGN_TAB(incr).txn_type||','||OUT_SIGN_TAB(incr).objid);
end loop;
end;
Error is thrown on "for incr in 1 .. OUT_SIGN_TAB.count" this line
Following is some related information.
the 3rd parameter of the procedure is a out parameter. it is a type of a PL/SQL table (SEARCH_SIGN_TAB_TYPE) which is available in database as follows.
TYPE "SEARCH_SIGN_TAB_TYPE" IS TABLE OF SEARCH_SIGN_TYPE
TYPE "SEARCH_SIGN_TYPE" AS OBJECT
(ref_no VARCHAR2(22),
ciref_no VARCHAR2(352),
ac_no VARCHAR2(22),
txn_type VARCHAR2(301),
objid VARCHAR2(1024))............

Answer 1

We don't have your rt843pq procedure, but when commenting that line out, everything works:
SQL> create TYPE "SEARCH_SIGN_TYPE" AS OBJECT
  2  (ref_no VARCHAR2(22),
  3  ciref_no VARCHAR2(352),
  4  ac_no VARCHAR2(22),
  5  txn_type VARCHAR2(301),
  6  objid VARCHAR2(1024))
  7  /
Type is aangemaakt.
SQL> create type "SEARCH_SIGN_TAB_TYPE" IS TABLE OF SEARCH_SIGN_TYPE
  2  /
Type is aangemaakt.
SQL> declare
  2    err_cd varchar2(1000);
  3    err_txt VARCHAR2(5000);
  4    no_of_recs number;
  5    out_sign_tab search_sign_tab_type:=search_sign_tab_type(search_sign_type(NULL,NULL,NULL,NULL,NULL));
  6    cntr_var number:=0;
  7  begin
  8    -- rt843pq('DWS','3000552485',out_sign_tab,no_of_recs,err_cd,err_txt);
  9    dbms_output.put_line('The error is ' ||err_cd);
10    dbms_output.put_line('The error is ' ||err_txt);
11    dbms_output.put_line('The cntr is ' ||cntr_var);
12    for incr in 1 .. OUT_SIGN_TAB.count
13    loop
14      cntr_var := cntr_var + 1 ;
15      Dbms_output.put_line(OUT_SIGN_TAB(incr).ref_no||','||OUT_SIGN_TAB(incr).ciref_no||','||OUT_SIGN_TAB(incr).ac_no||','||OUT_SIGN
TAB(incr).txntype||','||OUT_SIGN_TAB(incr).objid);
16    end loop;
17  end;
18  /
The error is
The error is
The cntr is 0
PL/SQL-procedure is geslaagd.Regards,
Rob.