Integrating with 3rd party system

Hi,

We need to integrate Bank with SAP ECC using SAP PI (Non SAP --> SAP PI --> SAP ECC).

MT940 Bank statement needs to be passed to SAP ECC using SAP PI.

Can someone suggest how can i integrate SAP PI with 3rd party system to receive MT940 file?

Basically i am confused at Inbound side (Non SAP --> SAP PI), which adapter to be used.

Thanks.