Hello Acrodoc,
I am not Hood but I can confirm for you that you can use both PNP and NPN transistor outputs because every single CSMIO input is fully isolated so inputs do not have a common ground or whatever call it.
So, there is absolutely no problem to either break the + or break the -.
If you have the signal as negative(0V), then wire to pins 14,15,16... and connect +24V from the power supply to pins 1,2,3. The opposite, if you have positive logic, then connect your sensor to pins 1,2,3 and put 0V at 14,15,16.
The only thing you should pay attention to is to not change the polarity.
My machine is wired exactly this way - 6 inputs are with pins 1,2,3,4,5,6 connected to +24V from power supply and I get the 0V to 14,15,16,17,18, 19 from limits switches.
The rest 6 inputs are positive logic -> emergency stop, alarm reset, etc...
In summary, connected whatever way you want (+ or -) but be sure to connect +(24V) to pins 1-12 and -(0V) to pins 12-25