B3800 Schneider Andover BACnet Field Controller Eight UI Eight DO Smart Sensor Port RS485 MS/TP Node

The B3800 is a native BACnet field controller from the Andover Continuum b3800 series, designed as a local controller for equipment-level installation rather than head-end placement. With eight universal inputs and eight digital outputs, it provides sufficient capacity to control small plant items or zones directly.

The controller handles temperatures, status contacts, and analog signals on the input side, while providing staged or on-off commands on the output side. It features a dedicated port for Andover smart temperature sensors, enabling local room or return air readings without additional signal conditioning.

Communicating as a master device on an RS-485 MS/TP field bus, these controllers were deployed across commercial buildings and remain in service due to their reliability. Sites with functioning MS/TP trunks can maintain plant operations by servicing these controllers rather than replacing entire automation systems.

Maintaining these controllers requires diligent record keeping, as the engineering toolset predates current maintenance staff, and application files often provide the only complete description of intended plant operations.

On MS/TP trunks, device instance numbers and baud rates must match the head end, with proper segment termination and continuous reference conductors. Intermittent communication faults typically result from improperly extended segments rather than controller failures.

During migration planning, these controllers can often remain in place as bridges while replacing the head end first.

This controller is primarily deployed in commercial plant rooms with smaller equipment items, where its eight inputs and eight outputs adequately control fan coils, small air handling units, or pump sets without requiring larger controllers.

Typical applications include:

• Office buildings and shopping centers with existing Andover Continuum systems, serving as replacement components to maintain floor operations
• Hospitals, universities, and government buildings requiring long-term controls infrastructure maintenance
• Industrial and laboratory facilities where local control must continue independently of supervisory systems
• Unmanned plant rooms where network outages should not disrupt control operations, thanks to local scheduling, trending, and alarm services