If I have 2 devices with LLDP enabled is it posible to poll data from only 1 device and create the DCF table for both devices?
You will need to have LLDP information from both devices.
On a given element A, LLDP (like any layer 2 discovery protocol such as CDP) will give you the remote information (remote chassis id, remote port id...) . For a DCF connection to be provisioned, the element and DCF interface ID of both ends need to be identified.
If you run the discovery on element A, IDP identifies the element and DCF interface ID of element A. However, the element ID and DCF Interface ID of the remote element are only known when you run the discovery on the remote element too. That's why you also need to have LLDP information on the remote element. A more elaborate explanation is available here : Implementing the Connectivity Discovery script | DataMiner Docs