Looking at the datasheet it would appear that the actuators could use a UART on the Axon. But rather than having separate Tx and Rx lines they just have one line and they show a diagram of the extra hardware you can add to do this. You would also need to use one digital I/O pin to control this extra hardware that switches the line between Tx and Rx. Then its just a matter of sending out the serial commands in the packet format they describe.