To setup more than one DT Link Hub to connect to the same series of data loggers, the DT Link hubs must be set with the same Network ID.
When the DT data loggers were first setup, they used the specific DTLink Hub network ID, any subsequent hubs must be changed to the same network ID.
On the Connections Tab, select Wireless Settings, then choose DTLink Settings. Under DTLink Hu Settings, choose 'Enable Edit'. You will be prompted for a password, enter the password is ‘coq’, then change the Network ID to the desired number (most likely the initial network ID for the original DTLink Hub).
Once the Network IDs are set to be the same, then both hubs will connect.
The Discover button will only work if you use the same hub each time, if you switch between hubs, you will have to select the data logger from the menu to be able to connect to them.