Delta update not working in generic datasource.

Hello friends,

I have created generic data source on MARA table with fields MATNR, NETGW, GEWEI, LAEDA(last changed date) where I kept generic delta field as laeda as shown in figure screenshot1.But when I go for delta update next day,it is not updating data and shows 0 record transferred as shown in screenshot 2.I have gone through many threads but still cannot find any solution.

Please help.

Thanks,

Urmil Kansara.

Screenshot1.

Screenshot2.