How many zones can the IQ Pro handle?

The Qolsys IQ Pro offers up to 128 zones, however, the term "zone" isn't the most accurate word to use with IQ systems. "Devices" would be the most proper terminology for the IQ Pro. 

This means the IQ Pro is capable of supporting up to 128 devices whether wired or wireless. As normal, wireless devices will always take up 1 single device slot on an IQ Panel. The wired side, however, counts all modules and wired inputs as individual devices. To break that down even further, each wired sensor input, keypad, zone expander, and power supply are also considered devices and count toward the total. 

It can be a little confusing, so here is an example of a short IQ Pro zone list to hopefully provide a better understanding:

- CORBUS module (main board) - Device 1 (or "zone" 1)
- Wired input 1 (on main board) - Device 2
- Wired input 2 - Device 3
- Wired Keypad - Device 4
- Zone Expander 1 - Device 5
- Wired input 1 (on expander 1) - Device 6 
- Wireless sensor - Device 7 
- Etc. 

So, as you can see, starting with the CORBUS, or the main board of the IQ Pro, each module, or sensor added basically gets added in the order they are enrolled on the panel. And since each device counts as a "zone" you can have a cumulative total of 128 devices, so it is important to consider this when building a very large IQ Pro system. For small or average sized systems, however, you'll have plenty of space left over.