I/O Systems - Select I/OAOS850

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.

The AOS850 is an Analog Output Signal Conditioning Module (16-bit) for use in Intrinsically safe applications (Zone 0) supporting 2-wire field devices and HART communications.

Features and benefits

  • Analog output for 2-wire field devices
  • Signal range: 0...20 mA or 4...20 mA
  • Can be used in hazardous areas
  • 16 bit D/A converter
  • Channel to channel galvanic isolation
  • Configurable output rise/fall times (down to 1 ms; with HART down to 20 ms)
  • Protected against wrong wiring
  • Diagnostics:
    • Loop supervision (open circuit and short circuit)
    • Hardware error supervision
    • Communication supervision
    • Internal power supervision
  • Support of HART field devices (up to HART application layer rev. 7):
    • HART Pass-Through
    • Cyclic read of up to two HART Device Variables
    • HART Device Validation
  • OSP (Output Set to Predetermined value)
  • 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