The property sheet for a pump link is shown below, This requires you to set a level at which the pump switches on and off, and a table of water elevation vs flowrate.
The pump can only come out of a detention basin, and the trigger level for the pump refers to the level of water in this basin. The DRAINS Utility Spreadsheet contains a worksheet for determining the elevation-flowrate relationship from the selected pump's H-Q curve and the rising main characteristics. An elevation-flowrate relationship developed from a spreadsheet can be imported into the Pump property sheet using the Paste Table button.