Advance Application Controller for Fan Coil units, Unit Ventilators and Heat Pumps

The DAC-304 is a fully programmable, Native BACnet™ Advanced Application Controller that communicates on an RS-485 LAN using the BACnet MS/TP protocol. The DAC-304 is designed for a wide-range of applications that have small local I/O requirements. It also supports BACstats and other Delta LINKnet devices.


The DAC-304 is suitable for controlling various packaged units and equipment with small I/O requirements such as Fan Coil units, Unit Ventilators and Heat Pumps.

The fully programmable DAC-304 can be tailored to specific applications by creating and modifying BACnet objects and GCL+ programs.


  • Native BACnet firmware
  • BACnet MS/TP communications
  • Supports 4 BACstat network sensors on LINKnet for room sensing and control or 2 Delta Field Modules on LINKnet for I/O expansion
  • Easy to mount housing
  • Fully programmable in GCL+
  • Application database can be flash loaded over the network
  • Controller firmware can be flash loaded over the network
  • Supports Modbus capability via flash loading in the field
  • Supports flash loading Modbus upgrades via hardware key
  • Derived Network Addressing (DNA) for simple integration into a standard network architecture
  • Service port

BACnet Device Profile

BACnet Advanced Application Controller (B-AAC)


3 Universal inputs - 10 bit (supporting 0-5v,

0-10V, 10kΩ, 4-20mA)


4 Binary triac outputs

Jumper selection for internal or external power on binary outputs

LED status indication of each output


32-bit processor

1 MB (8 megabit) Flash memory

127 KB SRAM (for database)

LED indication of CPU and SCAN status

Device Addressing

Set via DIP switch and jumpers, or software setup

Communications Ports

Main LAN (NET1)

BACnet MS/TP @ 9600, 19200, 38400 or 76800 bps (default) (maximum of 99 devices per BACnet MS/TP segment)


Delta LINKnet @ 76800 bps (maximum 4 devices on LINKnet, with no more than 2 DFM devices)


Removable screw-type terminal connectors

Wiring Class

Class 2


24 VAC

6VA, 54VA maximum with fully loaded BO’s


32° to 131°F (0° to 55°C)

10 - 90% RH (non-condensing)


7 5/8 x 4 x 1 7/8 in. (19.2 x 10.2 x 4.8 cm) with housing

0.551 lb. (250 g) with housing





C-UL Listed

UL 916 Listed

BTL Listed

  • MS/TP Application Controllers (DAC)