DFM-400 / DFM-404 / DFM-440

DFM-400 Remotely Expandable IO Controller by Delta Controls

The DFM-400/404/440 provide remotely expandable I/O to Delta’s BACnet™ Controllers. These field modules provide 4 universal inputs, in three different output configurations, and are capable of communicating on Delta’s LINKnet network or directly on an RS-485 BACnet MS/TP network (DFM-400 model only).

When connected to a LINKnet network the DFM-400/404/440 provides remote input and programmable output capabilities to the controller. When connected on the MS/TP network (DFM-400 only) the modules function as independent BACnet devices with inputs accessible over the BACnet MS/TP network.


The DFM-400/404/440 suits a diverse range of application needs where additional inputs and outputs are required, or where a small number of I/O’s are remotely located.


  • Native BACnet device (DFM-400 only) supporting communication on an RS-485 BACnet MS/TP network
  • Supports communicating on LINKnet
  • Easy-to-mount housing
  • Derived Network Addressing (DNA) for simple integration into a standard network architecture
  • Extended temperature range for extreme ambient situations

BACnet Device Profile

BACnet Application Specific Controller (B-ASC)


4 Universal inputs – 10 bit (supporting 0-5v, 0-10v, 10kΩ, 4-20mA)


DFM-400: None

DFM-404: 4 Binary triac outputs, 0.5 Amp @ 24 VAC, jumper selection for internal or external power on binary outputs, LED status indication

DFM-440: 4 Analog outputs (0-10v), maximum 20 mA, LED status indication


8-bit Processor with internal A/D, Flash and RAM

Device Address

LINKnet Connection, set via DIP switch and jumpers, DIP switch address range: 1 to 12

Communications Ports

LINKnet Connection, Delta LINKnet @ 76800 bps BACnet MS/TP connection @ 9600, 19200, 38400 or 76800 bps(default) (maximum of 99 controllers per BACnet MS/TP segment) (DFM-400 only)


Removable screw-type terminal connectors

Wiring Class

Class 2


24 VAC

6 VA

DFM-400: 4 VA

DFM-404: 52 VA

DFM-440: 6 VA


-40° to 140°F (-40° to 60°C), with enclosure

10 - 90% RH (non-condensing)

Internal electronics rated from -40° to 85°


5.5 x 4.0 x 1.78 in. (13.75 x 10 x 4.8 cm) with housing

0.38 lb. (171 g) with housing





UL 916 Listed

UL 864 Listed (DFM-400-UL864, DFM-404-UL864, DFM-440-UL864 only)

  • IO Expansion Modules (DFMs)