Select I/O is an Ethernet networked, single channel granular I/O system for the ABB Ability™ System 800xA automation platform. Select I/O helps decouple project tasks, minimizes the impact of late changes and supports standardization of I/O cabinetry ensuring automation projects are delivered on-time and under budget. A Signal Conditioning Module (SCM) performs the necessary signal conditioning and powering of the connected field device for one I/O channel.

DOS880 a Digital Output 24 V/0.6 A Signal Conditioning Module for High Integrity. Certified for SIL3.


System 800xA offers flexible and modular I/O solutions through fieldbus technologies, wireless I/O and hardwired I/O systems like S800 and S900. The system is now enhanced with Select I/O that allows to condition each signal coming from the field individually. Select I/O is Ethernet connected and consist of single channel granular Signal Conditioning Modules (SCM).

Features and benefits

• Digital output for 2-wire field devices
• 24 V/0.6 A current sourcing
• Can be used in hazardous areas
• Certified for Functional safety
• Field power sourced from the power injection.
• Short circuit proof, electronically current limited to 0.6 A
• Built-in inductive load suppression, free-wheeling diode
• Galvanic isolation
• Protected against wrong wiring

• Diagnostics:
– Loop supervision (open circuit and short circuit)
– Hardware error supervision
– Communication supervision
– Internal power supervision
– Power injection supervision

• Single loop granularity - each SCM handles a single channel.
• Supports hot swap
• Mechanical locking slider which turns off field device power and/or output before removal.
• Field disconnect function which can galvanically separate the field loop wiring from the SCM during commissioning and maintenance.
• All SCMs have electronic current limitation
• Mechanical keying to prevent insertion of wrong module type after commissioning.
• 24V DC powered through Modulebus
• Configurable through parameters
• LED indicators on the SCM indicate the operational state of the module.
• Certified for SIL3