ABPER Problem for BAPI_ACC_DOCUMENT_POST

Hello;

I'm using BAPI_ACC_DOCUMENT_POST to create FI G/L Documents.

In customizing ABPER(Settlement period) is a obligatory field for only one HKONT (General Ledger Account).

There is no problem for other HKONTs.

But there is no ABPER field in BAPI's imports/tables/changings structure

or table.

When ABPER field is empty , bapi isn't create documents.

Error Message : u201CField Settl.per. is a required field for G/L account 600 1810200000u201D

Mesaage Class : F5 u2013 Number : 808

How can I solve this problem.

Thanks.