Design

Device Instance Number Planning

Device Instance ID - Numbering Guide 

ASHRAE states: Instance numbering can range from 0 through 4194302.

Instance ID Numbering Guide: 

Instance ID numbering must be unique “system wide”, no duplicates. 

If we don’t know what Instances numbers are used on a customer’s site, dig in and find out. Instance ID numbering is NOT the same as Network ID numbering. Network ID numbering is explained in a different section. 

When dealing with a site that does not utilize a BACnet Instance ID “standard”, these are the guidelines that should be followed. 

This Design will allow: devices in 418 buildings, 99 panels per building (or BLN), with up to 99 MSTP devices per panel. NOTE- we rarely have more than 50 PXC panels per BLN… mega BLNs have more problems than smaller BLNs.

Instance Numbering Rules

Applies to: PXC Panels, TEC/FLN, 3rd party MSTP

XXX + XX + XX = XXXXXXX (5 to 7 digits)

Building number = 001-418 (First 3 digits)

Panel or Devices number = 00-99 Note. (Middle 2 Digits)

MSTP Devices- based on the MAC Address = 01-99 (Last 2 Digits)

Example below: 2 Buildings, 2 PXC panels in each building, 2 TECs in each panel. 

Building 1~ 

Panel #1- 

010100 PXC 

010101 TEC1 

010102 TEC2 

Panel #2- 

010200 PXC 

010201 TEC1 

010202 TEC2 

Don’t kill yourself trying to match building numbers, example: Building 6005, this won’t fit. Simply use an excel sheet that lists all buildings and how they will be defined in the Instance ID numbering design.

On really large buildings you can assign more than one designation number to the same building. (See “Lincoln Hall” below for example).

Example building number convention: 

Building - Instance Designation 

2001 - 1 

2002 - 2 

2002B - 3 

2033 - 10 

3001 - 20 

Lincoln Hall - 21 

Lincoln Hall - 22

RA4 - 23 

Nash Hall - 24 

3005 – 25