Hello, I'm new member of this forum, but I've been reading as an unregistered user for a while. I'm a development engineer looking for a bit of advice.
Since each BACnet device object_identifier has to be unique on the entire internetwork, I was wondering if there are any addressing schemes in use, so we can manufacture our products with a unique device instance (the 22 bit) that no-one else is using? (Sort of like the LON neuron ID being totally unique)
The standard (or is it the BTL? I forgot.) says that this device instance has to be configurable by the installer, and I've seen a couple of ways that other vendors obtain this:
1) By DIP switches on the device or similar (this takes 22 switches!)
2) Configurable by external device and software, like a PC tool or another BACnet device
3) Configurable by display and buttons on the device.
My problems is that with our products, none of the above methods are optimal, so I was hoping there was another way to ensure a unique device instance, so we didn't have to give the installer the option of changing it?
Or are there any options for this that I've left out? I'm pretty sure there are no addressing scemes around, but it never hurts to ask.
I've seen a vendor using the MS/TP MAC address as the device instance as well, but this sets a limit of 127 devices (if master), so that isn't an option to us.
I hope someone has some input on device instances - what is possible, and what is not?