Product Overview
When field device signals need reliable acquisition in harsh industrial environments, the ABB DI818 digital input module delivers consistent performance. This 32-channel module accepts 24 V DC current sinking inputs, making it a solid choice for monitoring sensors, limit switches, and pushbuttons. Part of the ABB S800 I/O family, the DI818 integrates seamlessly into distributed control systems.
Technical Specifications Breakdown
The DI818 operates with an input voltage range of 18 to 30 V DC, drawing 4.3 mA at 24 V. Inputs are organized into two isolated groups of 16 channels, each with a voltage supervision input. Key electrical specs include an input impedance of 5.6 kΩ, digital filter times selectable from 2 to 16 ms, and a maximum field cable length of 600 meters. The module dissipates typically 3.1 W and consumes 70 mA from the +5 V ModuleBus plus 25 mA from the +24 V external supply. Isolation is groupwise from ground, with a rated insulation voltage of 50 V and a dielectric test voltage of 500 V AC.
Industry Applications
In manufacturing lines, the DI818 monitors proximity sensors and limit switches across two independent zones, thanks to its group isolation. The voltage supervision feature alerts operators if a sensor power supply fails, reducing troubleshooting time. For process plants, the module's 600-meter cable length supports remote field devices without signal degradation. The selectable filter times (2, 4, 8, 16 ms) help reject electrical noise in electrically noisy environments.
Installation & Setup Guidance
Mount the DI818 onto an S800 MTU like the TU818 or TU819. Ensure the module is properly keyed (keying code EA) to prevent incorrect insertion. Connect field wiring to the MTU terminals, observing polarity for 24 V DC sinking inputs. The module's front panel LEDs indicate channel status (0 or 1), plus fault, run, and warning conditions. For vertical mounting in compact MTUs, limit ambient temperature to 40 °C; otherwise, 55 °C max applies.
Maintenance & Reliability
From a maintenance perspective, the DI818 offers straightforward diagnostics. Front LEDs show channel states and module health, while the voltage supervision per group flags power loss. Periodic inspection of LED patterns and checking for module warnings helps catch issues early. The module's IP20 protection suits clean, dry control cabinets. With no moving parts and robust EMC protection (EN 61000-6-4 and EN 61000-6-2), the DI818 provides long service life with minimal intervention.
Compatibility & Integration
The DI818 works with ABB S800 I/O MTUs including TU818, TU819, and TU830. It communicates via the ModuleBus, supporting error signal reading for voltage supervision. The module is CE marked and complies with electrical safety standards EN 61010-1 and UL 61010-1. Marine certifications from ABS, BV, DNV, and LR expand its use in shipboard automation.
Selection Guide & Purchasing Advice
Before ordering, confirm your system uses S800 I/O and that the MTU matches (TU818, TU819, or TU830). Verify the input type—24 V DC sinking—matches your field devices. The DI818 does not support HART, SOE, redundancy, or high-integrity configurations. For current availability and lifecycle status, contact SpareTechPLC. We stock the DI818 (3BSE069052R1) and can advise on replacements if needed.
Frequently Asked Questions
Q: What is the input voltage range for the DI818?
A: The DI818 accepts 18 to 30 V DC inputs, with a nominal 24 V DC.
Q: How many channels does the DI818 have and how are they grouped?
A: It has 32 channels divided into two isolated groups of 16, each with voltage supervision.
Q: Can the DI818 be used with redundant systems?
A: No, the DI818 does not support redundancy; it is a standard non-redundant module.
Q: What filter times are available on the DI818?
A: Digital filter times are selectable at 2, 4, 8, or 16 ms.
Q: What is the maximum cable length for field wiring?
A: The maximum field cable length is 600 meters (656 yards).
