Two ax500 on a serial port

I need to connect 2 different ax500 to a serial port to control a total of 4 motors.
I've read in the forum the feature to assign an address to evry controller using roborun (storing the value in flash) but i can't find this option.
Moreover, how can i send a command via rs232 to one controller or the other?

Thank you.
Alessandro

This was a feature that was included in a beta version of the firmware but that was not included in the final release.

The function worked but required an unusual daisy chain cabling of the RS3232 ports.

If possible, it would be best for you to add a serial port to your PC using USB to serial adapters.

Later i'm planing to control the application by a microcontroller and the microcontrollers only have one serial bus. How can i solve the problem?