Quote Originally Posted by zzip7 View Post
Does anyone know why JCI says we cannot use MAC addresses 1 to 3 with their products? What are they reserving this for? I've never seen a rule like this on any other BACnet products I've worked with. Does this just apply to their products, or will there be issues if I connect my (non-JCI) device and address it in that range.

It's in this tech doc on page 19, but they don't make it clear why they have this rule.

Attachment 803712

Other people answered this, but it is primarily because of the display. If I remember right, some devices can default back to address 1 if they go back to factory default. Heard a rumor of someone having a Senva bacnet CO sensor do that to him two years after it was installed.