BACnet Building Controller (40 I/O)

BTL B-BC certified; 16 Universal Inputs, 16 Relay, 8 Analog Outputs

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BACnet Building Controller (40 I/O)


  • Onboard Ethernet connectivity
  • BACnet-IP to BACnet-MS/TP routing
  • XBee pad supports optional WiFi module
  • 16 Universal inputs (multiplex up to 64)
  • 16 Form A relays + 8 analog outputs
  • 3xRS-485 ports; 2 local, 1 system bus
  • Battery-backed hardware clock
  • Rugged stainless steel enclosure
  • USB Host and USB service ports
  • Modbus RTU Master and BACnet MS/TP interfaces


The 3-9540 BTL B-BC certified BACnet Building Controller featuring 4o Input/Output points and a BACnet MS/TP interface that can supervise sub-networks of 1-6100 Airflow Controllers, 3-6115 Airflow controllers, or other BACnet devices, a battery-backed real-time clock, and an optional Modbus RTU Master interface.

The 16 onboard Universal inputs can be multiplexed to provide up to 64 total inputs, while 16 Form A relay outputs and 8 analog outputs offer control points for mechanical equipment and systems. Transient voltage suppressors and a 100 mA polyswitch provide a uniquely high degree of protection from power spikes.

The controller is often applied to supervise facilities, and to control mechanical equipment including Air Handlers, Chillers and other building mechanical equipment. In complex higher point count applications the controller can power a single USB IO Expansion module to add 20 I/O points (8 Universal inputs and 8 relay + 4 analog outputs), or can be integrated with up to 3 independently powered USB IO Expansion modules to add 60 I/O points.

An Ethernet port can provide BACnet-IP to MS/TP routing, as well as offering front ends very fast data access and ASI Visual Expert graphical configuration software a secure tunnel to remotely update controller configurations.  A USB service port provides extremely fast direct local communication with configuration and networking software; a USB Host provides rapid on-site loading of firmware upgrades.

If multiple protocols are needed, a BACnet system bus can operate with a Modbus RTU Master local bus 1 and an ASI legacy protocol sub-network on local bus 2. A Modbus RTU Master interface can be selected for either or both of the local buses to control and monitor Modbus slave devices including variable frequency drives (VFD’s), smart power meters, digital communicating thermostats, Lighting controllers and panels, pressure monitors, etc. An ASI Controls Energy Management System with VFD’s and other energy saving devices can reduce building energy consumption and lower operating costs.

The controller provides energy management and control of a wide range of building systems including air handlers, chillers, cooling towers, boilers, pumps, lighting, etc. Applications range from autonomous control of retail stores, branch banks, and telephone company buildings to networked control of very large buildings.  A native demand control algorithm can be configured to automatically make setpoint adjustments and duty-cycle or idle equipment when load is forecast to exceed a preset maximum kW demand control set-point. An Optimum Start sequence uses historical and current data to minimize energy used to get the building suitably conditioned for occupancy.

ASI Visual Expert graphical configuration software provides a comprehensive library of objects that can be dragged and dropped to program sequences of operation. Configuration data stored on the device can be uploaded to any instance of Visual Expert software, either through plug-in connectivity on the jobsite or remotely over a network connection.

The device uses flash memory for persistent program and data storage and features an isolated switching power supply for AC or DC operation and a battery-backed real-time clock for stand-alone or network supervisor functionality. Onboard data trending and alarm/event initiation; advanced scheduling and calendar features allow special time schedules for flexible occupancy settings such as educational facilities, or for applications like retail networks who schedule special hours around holidays. Can automatically backup configuration and trend data to qualified SD cards.