PO payment terms update using FUNCTION 'BBP_PD_PO_UPDATE'

Hi,

I'm using the FM 'BBP_PD_PO_UPDATE' followed by 'BB_PD_PO_SAVE' to mass update the payment terms on the PO. However, this is affecting the fields BBP_PDHGP-VAL_PO_E & BBP_DDIGP-VAl_PO_E causing these values to reduce. I have not explicitely passed these parameters to the BAPI but it seems to be getting affected as part of the background process. Is there a way to avoid updating all other fields other than the PAYMENT TERMS ?

Regards,
Esha