ASCII and EBCDIC have fundamentally different collating sequences. ASCII format is used on the Visual LANSA while EBCDIC is used by the IBM i.
For example, in EBCDIC the numbers '0' -> '9' are collated after the letters of the English alphabet. In ASCII, they are collated before the alphabet. Your data may now appear in a different sequence.
In sensibly designed modern applications, this should not affect the overall processing of an application, although it may affect the sequence that some individual applications present information.