TRANSPONDER CODE ASSIGNMENT NOT CORRECT ON DEP FOR ACR MLG.

Narrative

ON DEP FROM CLT RWY 18R; DEP CTL SAID THEY WERE NOT RECEIVING PROPER TRANSPONDER CODE. AS THE FO PNF WORKING THE RADIO; I ASKED WHAT THEY SHOWED TO BE THE PROPER CODE. I SET THE PROPER CODE. FLT THEN PROCEEDED NORMALLY TO DEST. WE WERE GIVEN HDG TO SID (BY NAME). ALL ATC INSTRUCTIONS WERE COMPLIED WITH AND NO OTHER QUESTIONS AROSE CONCERNING OUR FLT. TRYING TO DETERMINE WHY PROPER CODE WAS NOT SET IN TRANSPONDER I TRIED TO RECONSTRUCT MY ACTIONS AS THE FO. UPON BOARDING THE ACFT I DID THE NORMAL PREFLT AND PROGRAMMED THE PERFORMANCE DATA COMPUTER AND THE ACARS. CLT HAS THE PRE-DEP CLRNC PROGRAM IN EFFECT. I SET ATC IN THE ACARS TO GET THE CLRNC. IT IS NOT NECESSARY TO CALL CLRNC WHEN USING THIS SYS. I PERFORMED THIS STEP BUT WAS DISTR BEFORE THE STEP WAS COMPLETE; AND DID NOT NOTE THE TRANSPONDER CODE. I THEN DID AN OUTSIDE PREFLT UPON RETURN TO THE ACFT THE CAPT HAD THE PRINTED COMPANY RELEASE. I CHKED IT AND NOTED THE ACFT NUMBER; RTE OF FLT; SID; ALT; FUEL LOAD ETC. THIS IS OUR NORMAL TRIP AND IT ALL CHKED OUT. THIS CAUSED US TO HAVE POSSIBLY DEPARTED CLT WITHOUT ACTUALLY RECEIVING THE ATC FLT PLAN (CLRNC) ON THE COMPUTER. ALL COMS WITH GND WHEN WE CALLED FOR TAXI WERE NORMAL; ALL TWR COMS WERE NORMAL FOR TAXI; ALL DEP COMS WERE NORMAL. ALSO ALL ENRTE COMS WERE NORMAL NO ONE MADE ANY REF TO A PROBLEM CONCERNING OUR FLT OR CLRNC. THE FLT PROCEEDED NORMALLY AND UNEVENTFULLY. UPON REACHING OUR DEST (ROA) I CALLED THE CLT CTL TWR AND TOLD THEM WHO I WAS AND ASKED IF THERE WERE ANY PROBLEMS OR QUESTIONS CONCERNING OUR FLT. THEY REPLIED THERE WERE NO PROBLEMS OR QUESTIONS. POSSIBLE FAILURE ON MY PART (FO) TO COMPLETE COMPUTER PROGRAM AND NOTE TRANSPONDER CODE. PROCS WERE FOLLOWED AND OUTSIDE DISTR MAY HAVE CAUSED INTERRUPTION OF NORMAL SEQUENCE. I DO NOT SEE THIS AS BEING A RECURRING OR COMMON PROBLEM.