The CX-2 and MX-1 user manuals describe the procedure for setting the AC power voltage to either 110/230 V or 120/245 V by moving the plug at connector PL124 on the PCB. See photo below.
The procedure in the user manuals is correct for early fixtures, but a minor PCB redesign meant that setting the voltage on later model MX-1 and CX-2 fixtures is slightly different. Below photo shows the plug on later PCBs.
On all PCBs, the plug at PL124 must be installed on three pins so that the red wire is next to the word "RED" and the connector is lined up with the box printed on the PCB. On later PCBs, this means that the red wire must connect to the pin closest to the edge of the PCB for 110/230 V power or the pin furthest away from the edge of the PCB for 120/245 V power.