The alarm input of the CNC720 can be configured to be NPN or PNP. Default it is set to NPN, this means the inputs need to be connected to GROUND to activate.

On the CNC760 it's not possible to select the input type, default it will be NPN

Alarm outputs of drivers are often open-collectors types, the benefit is that you can actually connect the outputs together so you would only need one wire. This is called 'wired-or'. 

If you use the CNC720 controller it will only have this one alarm input, however, if you use the CNC720 Breakout board you can use the 4 inputs on the board or just one of them.

Below each alarm output is separately wired to the alarm output: 

Optional, if this is easier for your setup you can combine the outputs already at the drives themselves, this would look like this:

You can test the alarm input by connecting a wire to the alarm input and connecting it to the ground. As a result, you should see in the I/O screen of our software that it is detected.

Do not forget to configure in the setup what should happen if the drive is activated.

The behavior can be set by these values:

0,1,2No action
3Stop on low
4Stop on high
5Slow feed on low
6Slow feed on high
7Warning on low
8Warning on high