pcb - signal ground and power ground

I'm making a PCB with two ground signals, power ground and signal ground. These two shall be connected together at one spot on the PCB, after recommendations from the datasheet. But how is this done in the schematic? I can't simply connect these two together, since it will then be interpreted as one net and give a DRC error. Any help is appreciated. The schematic is done in Altium Designer.

Here is the schematic of the demo board which I have based my design on, a connection between SGND and GND is done on the bottom if the schematic.

http://cds.linear.com/docs/en/demo-board-schematic/DC2044A-2-SCH.PDF