TFxB Series Thermostat Controller
Page | 2
Introduction
This document provides information on using the Neptronic thermostat controller communications feature. This
product provides a BACnet
®
network interface between BACnet
®
client devices and Neptronic controllers. It
uses the BACnet
®
Master Slave/Token Passing (MS/TP) protocol at the BACnet
®
MAC layer.
This document assumes you are familiar with BACnet
®
and BACnet
®
terminology.
BACnet
®
Overview
Performance
The thermostat controller uses a synchronous implementation for BACnet
®
messages. Each BACnet
®
confirmed service request is answered as quickly as possible without using Reply Postponed. In particular,
MS/TP implementation performs within Tusage_delay of 15ms in order to assure Tusage_timeout values within
20ms.
Support for MS/TP
The thermostat controller supports a Full Master Node state machine for MS/TP. All parameters are configured
via the thermostat menu or via the BACnet
®
WriteProperty service. Changes made via the WriteProperty take
effect immediately and does not require a restart of the thermostat controller. For more information the
configurable properties, please refer to the
Getting Started
section on page 3. For more information on the
thermostat menu, please refer to the thermostat controller’s
Specification & Installation Manual
for more details.
BIBB Support
The thermostat controller generally behaves as a B-ASC type profile server. The following specific BIBBs are
supported per their relevant definitions in Annex K to BACnet
®
: DS-RP-B, DS-RPM-B, DS-WP-B, DS-WPM-B,
DM-DDB-B, DM-DOB-B, DM-DCC-B
Object Support (in general)
The thermostat controller supports a table-based fixed list of BACnet
®
-visible values which appear as
Present_Values of various BACnet
®
standard object types, in addition to a Device object.
Alarms
Although the thermostat controller supports the ability to indicate various alarm conditions through value
changes in properties of several of its objects, it
does not
generate BACnet
®
Event Notifications.
Features
Neptronic thermostat controllers also offer the following time-saving features.
Auto Baud Rate Detection
The thermostat controller automatically configures its baud rate by detecting the network speed upon
connection.
Auto Device Instance Configuration
The thermostat controller automatically configures its device instance to MAC address.
Copy Configuration
Copy the thermostat controller’s entire configuration and broadcast it to other thermostat controllers of the
same type on the same network.
