EdingCNC CPU5A4E Manual page 12

These are the steps to follow:
In the dialog check the "enable axis 4" checkbox, enter tour name and press
get request code:
Send the request code to the supplier.
Copy and paste it into an email and send it to your USBCNC supplier.
To do this double click the code, press ctrl-c, in your e-mail press control-v.
Your suplier will send you a activation code.
Copy and paste this into the activation code area. then press activate.
Do what the dialog tells you, press ok twice, press save changes. and restart.
When you press the CPU-OPT button again, you will see that the 4th
axis is enabled and that it is registered with your name.