Altium Differential Pair and Tuning Length Routing

Differential Pair Rounting

Schematic Side:

This test board shows that to create two different differential pairs first you must connect the ends with a wire (Place, Wire), then (Place, Directives, Differential Pair) symbol onto the wire. No need to name it anything. When it dropped down on the PCB side it is recognized specifically as a differential pair class. Just drop it down. Next (Place, Net Label)  onto the same wire and in my case I called it the top one DRV_N. A differential pair needs a negative and a positive net. Connector pin #2 is done the same way with the positive net.
Connector pin #3 and #4 is the second differential pair. Pin #3 has a net name of  DRV1_N and pin #4 has a net name of DRV1_P. Both wires have differential pair symbols on them as well.

Now that these two pairs have the directives and net labels attached, on the PCB end Classes will automatically assigned.

PCB Board Side:

Once the board is set up with the connectors imported and placed under (Design, Classes) you will see under the Differential Pair Classes Folder that DRV and DRV1 under the Members  column.

Under PCB, PCB, select All Differential Pairs and you will see that both DRV and DRV1 pairs have automatically been assigned the positive and negative nets.

Now just set up the Track Width and Pair routing rules and you are all set.

To route the board select (Place, Interactive Differential Pair Routing) and select one of the two pins on the connector. It will automatically select the other and route it for you. Sweet!

Interactive net tuning

Schematic Side:

Interactive net tuning is even easier to set up. Wire up the connectors and (Place, Net Labels) and (Place, Directives, Net Class) on each wire. I have named the Net Labels each a different name but each Net Class all named the same.

PCB Side:

Now under (Design, Classes) under the Net Classes folder all four of your Tuned_Nets will show up, each named differently.

Set up the Tuned Net rule under (Design Rules, Matched Net Lengths, MatchedLengths)

Now when you (Place, Interactive Routing) all four tracks they will route any way you like but will cause an error when you (Tools, Design Rules Check) because they are all different lengths if not all perfectly straight. Once routed on a section of line select (Tools, Interactive Length Tuning) and drag your mouse around. Pressing 1,2,3 or 4 will adjust the tuning size. Try and get it on the green line between the two yellow lines.

To verify that all four lines are the same length (within 100mil) according to my rule, (Edit, Select, Net) so the net is white and then (Reports, Measure Selected Objects).