Hi Sudheer,
One of the most common oncode conditions that i encountered is 612, which means that the runtime found an invalid data and tried to convert it into a char string. Whenever u r doing a GET DATA() or PUT DATA() for a char string and u pass the input wrongly(like not inside quotes or length greater than declared) u'll receive an oncode between 601 and 639 in the sysout of ur job step.
Hope this gets u a few pointers abt str conv errors...
