BACnet - A Data Communication Protocol for Building Automation and Control Networks

Abstract

Carl Neilson, BACnet International, 61 Seagirt Road, BC, V9Z 1A3.

This request for interpretation refers to the requirements presented in ANSI/ASHRAE Standard 135-2016, Clause 12.56, regarding activating changes.

Numerous properties in the Network Port object include the following language:

If this property is writable, then a successful write to this property shall set the Changes_Pending property to TRUE.

A value written to this property shall become effective when the device receives a ReinitializeDevice service request with a 'Reinitialized State of Device' of ACTIVATE_CHANGES or WARMSTART.

The above language implies that execution of ReinitializeDevice is required if the property is writable but there is no language that explicitly states that this is the case.

The description of the Changes_Pending property includes the following allowance:

It is a local matter as to whether or not resetting the device by means other than a ReinitializeDevice service with a 'Reinitialized State of Device' of ACTIVATE_CHANGES or WARMSTART discards pending changes, activates pending changes, or leaves the changes pending.