ABB DOS810 3BSE078768R1 Digital Output SCM Unit

Module Feature

3BSE078768R1 is ABB DOS810 signal conditioning module of Select I/O family for System 800xA DCS.

Single channel 24VDC sourcing digital output, rated 0.6A, electronic short-circuit protection and built-in freewheeling diode for inductive solenoid loads. 3060VDC galvanic isolation between field side and Modulebus backplane. It supports hot swap, redundant channel configuration, built-in field disconnect and loop diagnostics. Installed on TUS810 termination unit, suitable for 2-wire field solenoid valves, relay coils in refinery, chemical and power plant control cabinet.

Working principle

The module receives digital on/off command from 800xA controller via Modulebus.

Internal power switch drives 24VDC output to field 2-wire actuator. Inductive suppression circuit absorbs back EMF from solenoid coils. Continuous loop supervision detects open circuit, short circuit and abnormal load, and returns fault status to DCS controller. Field disconnect slider isolates field wiring safely during maintenance without powering down the whole rack.

Onboard components

Output power switching circuit, inductive freewheeling suppression diode, galvanic isolation barrier, Modulebus communication interface, electronic current limiting circuit, field disconnect switch, status LED bank and compact plug-in PCB housing.

LED indicators

Front LEDs indicate power, run status, field loop fault, Modulebus communication and module health status.

Hardware self‑diagnosis

Built-in supervision detects output short, open loop, overcurrent, communication loss, internal power fault and hardware anomaly. Configuration and fault diagnosis are completed by ABB Control Builder M / 800xA engineering workplace.

Programming softwareControl Builder M, used for channel logic setup, redundancy configuration, OSP predetermined safe state setting and fault log reading.

Electrical & Process Parameters

Model:3BSE078768R1 Brand:ABB Device type:DOS810 Select I/O Digital Output SCM Function:24VDC digital output drive for 2-wire solenoid valves and field actuators

Mechanical & Structure

Mounting:Plug-in into TUS810 MTU termination base Protection class:IP20 Housing:Compact plug-in SCM module

Environmental

Operating temperature:-40℃ ~ +70℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE Status:Original ABB 800xA DCS control I/O spare

Installation

Isolate field loop and Modulebus power before replacement.

Insert module into correct coded slot of MTU base, activate field disconnect slider before field wiring work, download I/O logic configuration, test on-off drive and loop fault diagnosis function after commissioning.

Interface

Modulebus backplane interface, field terminal via FTB field terminal block for 24VDC digital output loop.

Diagnostic

Loop fault alarm: Output short circuit, field wire open or load overload. No actuator action: No output command, field power missing or coil burnout. Module offline: MTU power loss, Modulebus failure or firmware version mismatch.

Product Brief

3BSE078768R1 DOS810 module, ABB Select I/O single-channel 24VDC 0.6A digital output spare for System 800xA DCS solenoid valve control cabinet replacement.