Description
ABB DI840 3BSE020836R1 Product Description
Product Overview
ABB DI840 3BSE020836R1 is a 16-channel 24 V DC digital input module belonging to the ABB S800 I/O family. It is designed for distributed process automation systems to acquire discrete signals from field devices such as switches, contacts, sensors, interlocks and equipment-status signals. The module supports both single and redundant applications, making it suitable for conventional PLC/DCS I/O as well as applications requiring higher availability.
The ABB DI840 3BSE020836R1 uses current-sinking inputs and provides optical isolation, input-status indication and advanced onboard diagnostics. A key function is Sequence of Events (SOE) recording with 1 ms resolution, allowing time-critical changes in digital signals to be captured for event analysis. The module also provides supervised and current-limited transducer power, reducing the need for separate field-power distribution hardware.
Within ABB System 800xA, Freelance and compatible S800 I/O architectures, DI840 3BSE020836R1 serves as a high-density field interface between discrete instrumentation and the control processor. Its combination of redundancy support, diagnostics and SOE functionality makes it particularly valuable in continuous-process applications where accurate status acquisition and event traceability are important.
Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | DI840 3BSE020836R1 |
| Manufacturer | ABB |
| Product Family | S800 I/O |
| Product Type | Digital Input Module |
| Number of Channels | 16 |
| Signal Specification | 24 V DC |
| Input Type | Current sinking |
| Input Voltage Range | 18–30 V DC |
| Logic “1” Input Range | 11–30 V |
| Logic “0” Input Range | -30 to +5 V |
| Nominal Input Current | 7 mA @ 24 V DC |
| Input Impedance | 3.3 kΩ |
| Isolation | Group isolated from ground |
| Rated Insulation Voltage | 50 V |
| Dielectric Test Voltage | 500 V AC |
| SOE | Yes |
| SOE Resolution | 1 ms |
| Digital Filter | 0–127 ms selectable |
| Redundancy | Supported |
| HART | No |
| Intrinsic Safety | No |
| High Integrity | No |
| Maximum Field Cable Length | 600 m |
| Power Dissipation | Approx. 2.7 W |
| Modulebus Current | 100 mA @ 5 V |
| Mounting | S800 MTU |
| Protection Class | IP20 |
| Operating Temperature | 0 to +55°C |
| Storage Temperature | -40 to +70°C |
| Dimensions | 45 × 119 × 102 mm |
| Weight | Approx. 0.15 kg |
ABB’s current hardware selector confirms the 3BSE020836R1 article number, 16-channel 24 V DC specification, current-sinking input, SOE, redundancy support and S800 mechanics. It also lists compatible MTUs including TU810, TU812, TU814, TU818, TU830, TU833, TU838, TU842, TU843 and TU852.
Main Features and Advantages
16-Channel 24 V DC Digital Input
The ABB DI840 3BSE020836R1 provides 16 digital input channels for 24 V DC field signals. Its current-sinking architecture allows it to acquire signals from a wide range of industrial switches, contacts and discrete sensors while maintaining a compact I/O footprint.
Sequence of Events Function
A major advantage of DI840 is its integrated SOE capability. Events can be recorded with 1 ms resolution, allowing the control system to determine the sequence and timing of rapidly changing field signals. This is valuable when investigating trips, alarms, interlocks or equipment-start sequences. ABB specifies an event-recording accuracy of 0 ms / +1.3 ms.
DI840 3BSE020836R1
Redundant or Single Operation
The module can operate in either single or redundant applications. This flexibility allows the same basic I/O hardware to be deployed in standard automation cabinets or architectures where continuous availability is a priority.
Advanced Onboard Diagnostics
DI840 incorporates diagnostics for both internal circuitry and field-related conditions. The module monitors process power and transducer supply conditions and provides fault, warning and channel-status indications through front-panel LEDs.
Supervised Transducer Power
The module provides supervised and current-limited sensor/transducer power, with one power output serving each pair of input channels. This arrangement can simplify field-device wiring while providing additional protection against excessive current and short-circuit conditions.
Electrical Isolation and EMC Protection
Each input channel incorporates current-limiting components, EMC protection and an optical isolation barrier. This helps protect the control electronics from disturbances originating in industrial field wiring and improves signal reliability in electrically noisy environments.
Flexible MTU Compatibility
The DI840 can be installed with several S800 Module Termination Units, including TU810, TU812, TU814, TU818, TU830, TU833, TU838, TU842, TU843 and TU852. This provides flexibility when integrating the module into different S800 cabinet and field-wiring arrangements.
Application Fields
ABB DI840 3BSE020836R1 is widely suited to PLC, DCS and distributed process-control applications where 24 V DC discrete signals must be acquired reliably. Typical signals include motor running feedback, valve-position switches, pump status, pressure-switch contacts, alarm contacts, permissive conditions and equipment interlocks.
In power generation and substations, DI840 can monitor breaker positions, protection contacts, auxiliary equipment status and plant interlocks. Its SOE capability is particularly useful for analyzing the exact sequence of events preceding a trip or abnormal operating condition.
In chemical and petrochemical plants, the module can acquire discrete signals from pumps, compressors, valves, process skids and safety-related field devices. The ability to timestamp events helps operators and maintenance engineers distinguish between the initiating event and subsequent process responses.
In oil and gas facilities, DI840 3BSE020836R1 can be integrated into S800 I/O stations used for production, compression, separation and utility systems. The module’s redundancy capability and diagnostics are beneficial in continuous-process environments where unexpected loss of I/O information can affect plant operation.
The module is also appropriate for metallurgy, pulp and paper, water treatment, pharmaceutical production and smart manufacturing. Its 600 m maximum field-cable length and selectable digital filtering make it practical for distributed field instrumentation, while the S800 architecture allows the module to communicate with higher-level ABB control platforms.
Related Products
- DI830 3BSE013210R1 — 16-channel 24 V DC S800 digital input module with SOE, arranged as two groups of eight channels; suitable where a different isolation/grouping architecture is required.
- DI831 3BSE013212R1 — Related 16-channel S800 digital input module designed for 48 V DC signals rather than the 24 V DC input of DI840.
- DI880 3BSE028586R1 — High-integrity S800 digital input module for applications requiring enhanced safety-related I/O functionality.
- DI890 3BSC690073R1 — S800 digital input module with an intrinsic-safety interface, intended for hazardous-area instrumentation.
- DI810 3BSE008508R1 — 24 V DC digital input module in the S800 family for standard discrete signal acquisition.
- DI818 3BSE069052R1 — Related S800 digital input module for alternative 24 V DC field-I/O requirements.
- DO840 3BSE020838R1 — Corresponding S800 digital output family member, used to send discrete control commands to field devices.
- TU810 — Compact S800 Module Termination Unit compatible with DI840 and used to provide the field-wiring interface.
- TU830 / TU833 — Alternative S800 MTUs compatible with DI840 for different cabinet and termination requirements.
- TU842 / TU843 — Additional compatible termination units for integrating DI840 into S800 I/O installations.
