The MA6410 driver has optocoupler inputs, these are intended for TTL driving. Other voltages are also possible, however an extra external resistor would be required.
The driver outputs of the iCNC600 are open-collector outputs. The actual open-collector output is designated with '-' , the common output of each output is the designated with a '+' This + is either 5.2V or 24V. Use JP4 to set the correct voltage you like to use.
So to drive the motor driver set JP4, the JP4 is default set to 24V. This can be changed to 5V, as requiered here.
After setting JP4 to 5V the connections are:
MA6410 - iCNC600
STEP+ - pin #3 STEP+
STEP- - pin #4 STEP-
DIR+ - pin #5 DIR+
DIR - - pin #6 DIR-
ENABLE+ - pin #1 ENABLE+
ENABLE- - pin #2 ENABLE-