Specifications

• Manufacturer: Westinghouse (Emerson)

• Model: 3A99859G04 (QHS‑R 486 / 56ACE)

• Type: Digital Input Module

• Architecture: Q‑Line, right‑side slot

• Channels: 32 isolated digital inputs

• Input Voltage: 24 VDC nominal (18–30 VDC)

• Isolation: 1000 Vrms channel‑to‑ground

• Response Time: <1 ms per channel

• Operating Temperature: 0 °C to 60 °C

• Power Supply: 24 VDC ±10%, typical 7 W

• Form Factor: Standard Q‑Line rack‑mount card

• Indicators: LED for power, communication, and channel status

• Compatibility: WDPF, legacy Ovation DCS

• Weight: Approx. 1.0 kg

Key Features

• 32‑channel density: Maximizes I/O capacity in a single slot.

• Right‑slot design: Matches Q‑Line rack layout for legacy systems.

• 1000 Vrms isolation: Protects against industrial noise and ground loops.

• High‑speed response: Suitable for fast interlock and status monitoring.

• Hot‑swap capable: Online replacement without system shutdown.

• LED diagnostics: Quick visual check of power, comms, and channel health.

• Legacy reliability: Built for long‑term operation in critical facilities.

Applications

• Power generation: Boiler/turbine interlocks, burner status, auxiliary equipment monitoring.

• Petrochemical: Valve position, pump status, safety circuit monitoring.

• Water treatment: Pump/valve status, level switch, flow switch inputs.

• Heavy industry: Conveyor interlocks, machine safety, limit switch monitoring.

• Spare part replacement for existing WDPF/Ovation systems.

Related Part Numbers

• 3A99859G01: QHS‑R 486 Digital I/O (right slot, 16DI+16DO)

• 3A99859G02: QHS‑L 486 Digital I/O (left slot, 16DI+16DO)

• 3A99859G03: 32DI Digital Input (left slot)

• 3A99858G01/G02: Analog I/O modules (right/left slot)

Notes

• Legacy component: Supplied primarily as a spare for installed WDPF/Ovation systems.

• For new projects, Emerson recommends modern Ovation I/O modules for enhanced diagnostics and performance.