Appendix: Entelizone Thermostat Time Synchronization - Delta enteliZONE eZNT-Wi Series Application Manual

Appendix: enteliZONE Thermostat Time Synchronization

Appendix: enteliZONE Thermostat Time Syn-
chronization
The eZNT and the eZNTW without Wi-Fi enteliZONE thermostats communicate using
MS/TP and behave like a normal DAC controller connected to the NET2 port of a
system controller that provides time synch.
The eZNT-Wi/ eZNTW-Wi has special requirements when it comes to time
synchronization. If you have a wireless network of enteliZONE thermostats, they do
not connect to the NET2 port of a system controller that provides time synch. With
Wi-Fi thermostats, you need to enter the network number of the Wi-Fi thermostats
into the system controller's Time Sync list in the DEV object. This system controller
acts as a Time Master and sends a time synch over the BACnet/IP network at a
specified interval. See "The Execution" topic within the No Historian/webserver and
no Internet connection section of KbA1748 Proper Setup of Time Synchronization
(TimeSync).
The eZNT-Wi/ eZNTW has a built-in real time clock (RTC) in its hardware that
provides a clock source. The device relies on its Time Master controller to send a
time synch over a BACnet/IP network to update this RTC clock at regular intervals.
When a power cycle (ON-OFF-ON) occurs, the eZNT-Wi/ eZNTW loses its time and
reverts to January 1, 2000 12 midnight. If the default time of 3600 seconds is used in
the Time Master and the eZNT-Wi/eZNTW experiences a power cycle, the eZNT-
Wi/eZNTW may restart from January 1, 2000 12 midnight and require up to an hour
before the time gets synchronized from its time master. The internal RTC does hold
the time when there is a soft reset or a watchdog timer reset. The eZNT-Wi, eZNTW
and eZNT do not support UTC and DST time.
Page 114 of 126 eZNT-Wi Programmable Wi-Fi Thermostat Application Guide
Edition 1.4