How is payment terms populated on a Invoice IDOC ?

Hi,

How does VBDKR-ZTERM_TX1 VBDKR-ZTERM_TX2 and VBDKR-ZTERM_TX3 get populated? Currently I see that in the INVOIC IDOC the payment term is populated from VBDKR-ZTERM_TX1 which is not based on payment terms. , I am getting the value 'Payable immediately without deduction'. I was wondering how did this value get populated which is different from the text maintained for paylemt term in table T052 table.

IDOC segment : E1EDK18-ZTERM_TXT

I see that the payment terms in the master table are carried onto Sales order and then to billing document which match the T052 value of the payment term but the IDOC is pulling some other value from some where.

Regards

Praneeth