maximum units dosing pumps can connect to p4 or P3.1?

I had P3.1 running perfectly with 4 Slave dosing pumps connected and fully occupied, But I wish to connect the KH director
with the system. What can I do? Can I connect the expension box with addition dosing pump or need to buy a stand alone pump and seperate with the
system？

P3 and P4 supports up to 16 dosing channels.

A KH Director does not count as a dosing pump and can therefore be connected to the ProfiLux as a regular PAB device.