ABB DO818 Digital Output Module

The ABB DO818, also cataloged as the DO818 Digital Output Module, operates as a dedicated hardware component for discrete actuator driving within S800 I/O platforms.

Hardware Specifications

Backplane Bus & Deterministic Processing

The ABB DO818 communicates across the S800 Modulebus backplane using deterministic polling protocols to drive up to 32 individual 24 VDC outputs. Internal backplane logic coordinates current-limiting status and group isolation while sustaining high communication velocity. Compatible with standard S800 controller firmware, the module maintains cyclic output execution speeds and ensures stable backplane signal integrity during high-density switching operations.

Frequently Asked Questions

Q: Can the DO818 module be inserted into an active S800 Modulebus backplane slot without removing power?

A: Yes. The DO818 supports S800 module insertion under power (hot-swap), provided the external 24 VDC field load supply is isolated to avoid current surges on output terminals during mating.

Q: What protection mechanism activates when a digital output channel exceeds the 0.5 A current limit?

A: Each output channel incorporates short-circuit and overcurrent thermal protection that automatically limits channel current and reports fault conditions back to the host CPU via Modulebus diagnostics.

Field Installation Guidelines

1. Lock the module onto the matching S800 Modulebus baseplate until the mounting latch clicks into place.
2. Connect external 24 VDC field power supply lines to dedicated power terminals using properly fused conductors.
3. Route field output wiring using shielded or twisted pair cables separated from AC power lines by at least 200 mm.
4. Keep total field cable lengths within the maximum allowed 600 meters to limit line resistance and inductive voltage spikes.