ABB AO845A-eA 3BSE045584R2 8-Channel Isolated Analog Output Module

AO845A-eA 3BSE045584R2 belongs to ABB S800 I/O series, matching AC800M controller and System 800xA DCS platform. It converts digital control commands into standard 4–20mA analog output signals to drive field regulating valves, inverters and dampers. Built-in HART transparent channel supports bidirectional communication with HART smart positioners to read valve feedback, fault status and remote calibration parameters.

Each channel provides full galvanic isolation with short-circuit and overcurrent self-protection, equipped with complete loop diagnosis functions. The module supports hot-swap online replacement without rack power interruption, compatible with TU845 terminal unit for field wiring. It is widely used as standard spare parts for process industries to maintain and expand analog regulation control loops.

Main Specifications

• Brand: ABB; Model: AO845A-eA, Part No.: 3BSE045584R2
• Channel: 8 fully isolated analog output channels, independent channel isolation 2500V AC
• Output signal: 4–20mA DC, maximum load resistance 750Ω per channel
• Core feature: HART pass-through communication for smart valve positioners
• Power consumption: Max 1.2A @ 24VDC, single-slot rack installation
• Diagnosis: Loop open-circuit, short-circuit, module fault detection with front status LED
• Environment: Operating temperature 0℃ ~ +60℃, CE/UL industrial certification
• Matching terminal base: TU845 terminal unit for field signal wiring
• Key design: Hot-swappable, configurable fail-safe output value during communication loss
• Application: Spare analog output hardware for industrial DCS closed-loop regulation

Core Functions

• Receive digital setpoint data from AC800M controller and convert into stable 4–20mA analog drive signals
• Drive HART intelligent valve positioners, variable frequency drives and regulating dampers to adjust flow, temperature and pressure
• HART transparent channel uploads valve stroke feedback, equipment fault codes and calibration parameters to DCS operation station
• Full channel galvanic isolation eliminates ground loop interference caused by multi-point field equipment grounding
• Independent overcurrent & short-circuit protection cuts off abnormal channels automatically to avoid module burnout
• Configurable safe output value prevents process runaway when communication between module and controller is interrupted
• Hot-swap function realizes online module replacement without affecting other normal control loops on the same rack

Application Scenarios

• Thermal power plant boiler feedwater, steam pressure and flue gas air volume regulating DCS cabinet layout
• Petrochemical reactor temperature, pipeline flow and pressure closed-loop control system construction
• Water treatment plant dosing valves, liquid level regulating actuator analog output matching projects
• On-site faulty AO module replacement and daily maintenance of ABB System 800xA DCS control systems
• Old production line automation transformation to expand multi-channel HART analog regulation capacity
• ABB S800 I/O series analog output spare parts inventory backup for energy and chemical enterprises
• Pharmaceutical, metallurgy continuous process production flow regulation control hardware maintenance projects