BACnet Field Control Device

BACnet Advanced Application Controller

DACU842B - BACnet Field Control Device - BACnet Advanced Application Controller


DACU842B is a standalone BACnet B-AAC class programmable controller with a LCD control panel. It is designed for monitor and control building electromechanical device, large AHU, clean room, fume hood, large-scale end device control. It uses 32-bit microprocessor core, transmission rate up to 76,800 bps, transmission distance up to 1,200 meter. DACU842B has 8 Universal Inputs(UI), 4 Binary Outputs(BO) and 2 Analog Outputs(AO).

In addition it also has EIMnet port can connect four EIM series of expansion modules, allowing you to expand in response to needs of various points. Another MSnet port can connect a external LCD screen control panel, for field engineer easy operation and access. DACU842B conforms to international BACnet MS/TP communication protocol and fully compatible with any BACnet system. It is absolutely the best product for your building.


  • Conforms to ASHRAE and ISO16484-1 defined BACnet AAC standard communication protocol, compatible with BACnet system.
  • A MS/TP(Master-Slave/Token-Passing) communication interface, with Peer to Peer function can read and write other DDC’s object, may issue a read (DS-RP-A/DS-RPM-A) and write (DS-WP-A) BACnet object properties function.
  • A MSnet communication interface can connect a MST20V, MST20S, DSP20U control panel or a MODBUS RTU device.
  • A EIMnet communication interface can connect 4 EIM I/O expansion modules.
  • Universal Input (UI) has 12-bit resolution, accept dry contact, pulse, 3K or 10KΩ NTC thermistor, 4 ~ 20mA or 0 ~ 10VDC signal.
  • Binary Output (BO) has a 1,000 VDC optical coupling isolation, 8A/250VAC/SPST relay (Relay), Status Indicator design. Each point has a manual on / off / auto three sections selector switch.
  • Analog Output (AO) has 12-bit resolution, can be selected by Internal parameters as 0 ~ 10VDC or 2 ~ 10VDC output signal, each point has a manual override/auto output control switch.
  • User’s control program can be downloaded, edited and saved in flash memory of the controller.    
  • Carry out calculations such as proportional, integral, differential, floating, logic, arithmetic and etc.
  • 150 Binary Value(BV) and 150 Analog Value(AV) points, the analog value adopts high precision floating-point calculation.
  • Priority control array by 16 for all BO, AO and BV.
  • Provide power failure backup function for all AI/BO/AO/BV/AV values keep in FRAM for at least 10 years.
  • Real-time clock, 2 Calendars, 12 Schedules, 4 Notification Class, 20 Event Enrollments standard BACnet object. Schedules and event enrollments support external object access function.

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