Honeywell HC900 Series Modules: FC-IOCHAS-0001R Redundant I/O Module

Technical Dossier

Product Details And Specifications

Honeywell HC900 Series Technical Notes

The Honeywell HC900 Process Controller series is a field-proven distributed control platform deployed across global heavy industry sectors including petrochemical refineries, nuclear auxiliary systems, offshore platforms, pulp and paper mills, and continuous chemical processing facilities. The HC900 architecture is characterized by its hybrid loop/logic control capability, combining PID regulatory control with sequential logic in a single rack-based chassis. Its modular I/O structure allows engineers to configure systems from small standalone controllers to large multi-rack distributed networks, making it one of the most scalable mid-range DCS platforms in Honeywell's catalog. The FC-IOCHAS-0001R is a redundant I/O chassis module within this series, providing the physical and electrical backbone for redundant I/O subsystem configurations — a critical requirement in safety-sensitive and high-availability process environments.

The Evolution of HC900 Architecture

The HC900 platform was introduced by Honeywell as a successor to earlier loop controller families, consolidating discrete PID controllers into a unified rack-based system with a deterministic scan cycle. Early revisions of the HC900 used a proprietary peer-to-peer communication bus between the controller and I/O racks, with limited redundancy options. Subsequent hardware generations introduced the redundant controller module (C50R/C70R) and the redundant I/O chassis infrastructure — of which the FC-IOCHAS-0001R is a core component — enabling 1:1 redundancy at both the CPU and I/O subsystem levels.

The architecture evolved through three primary phases: (1) single-controller, non-redundant I/O configurations suitable for non-critical loops; (2) redundant controller with standard I/O, used in semi-critical applications; and (3) fully redundant controller plus redundant I/O chassis, deployed in SIL-rated and high-availability environments. The FC-IOCHAS-0001R belongs to phase 3 of this evolution. Compatibility between hardware generations requires careful firmware version matching — mixing early-generation I/O modules with later chassis revisions can result in bus communication faults. DriveKNMS maintains cross-reference documentation for all known revision combinations.

HC900 Full Catalog & Functionalities (SKU List)

Controllers (CPU Modules)

• FC-QCPU-0001: HC900 C30 single-slot CPU, 300 I/O points max, Ethernet supervisory port
• FC-QCPU-0002: HC900 C50 CPU module, 900 I/O points, dual Ethernet, peer-to-peer bus
• FC-QCPU-0003: HC900 C70 CPU module, 2500 I/O points, high-speed scan, redundancy-ready
• FC-QCPU-0004: HC900 C75 CPU, enhanced memory, extended function block library
• FC-QCPU-R001: HC900 C50R redundant CPU module, primary unit for 1:1 CPU redundancy pair
• FC-QCPU-R002: HC900 C70R redundant CPU module, secondary/standby unit for C70 redundancy pair

I/O Chassis & Backplane Modules

• FC-IOCHAS-0001: HC900 standard I/O chassis, 12-slot, non-redundant configuration
• FC-IOCHAS-0001R: HC900 redundant I/O chassis module — provides dual-bus backplane for 1:1 I/O redundancy; required in all redundant I/O subsystem builds
• FC-IOCHAS-0002: HC900 8-slot I/O expansion chassis, non-redundant
• FC-IOCHAS-0003: HC900 remote I/O chassis, fiber-optic bus interface, up to 300m separation

Analog Input (AI) Modules

• FC-AI16-0001: 16-channel analog input, 4–20 mA / 1–5 VDC, 16-bit resolution
• FC-AI16-0002: 16-channel AI with HART pass-through, supports HART 5/6/7 field devices
• FC-AITC-0001: 8-channel thermocouple input, types J/K/T/E/R/S/B/N, CJC compensation
• FC-AIRTD-0001: 8-channel RTD input, 2/3/4-wire PT100/PT1000, 0.1°C resolution

Analog Output (AO) Modules

• FC-AO08-0001: 8-channel analog output, 4–20 mA, 12-bit resolution, loop-powered
• FC-AO08-0002: 8-channel AO with HART, isolated outputs, 750Ω max load

Digital Input (DI) Modules

• FC-DI16-0001: 16-channel digital input, 24 VDC, sink/source configurable
• FC-DI16-0002: 16-channel DI, 120 VAC, optically isolated, 10ms filter
• FC-DI32-0001: 32-channel DI, 24 VDC, high-density, 2×16 terminal block

Digital Output (DO) Modules

• FC-DO16-0001: 16-channel digital output, 24 VDC, 0.5A per channel, short-circuit protected
• FC-DO08-0001: 8-channel relay output, SPDT, 2A/250 VAC, mechanical relay

Communication & Network Adapters

• FC-RSWT-0001: HC900 Ethernet switch module, 4-port managed, DIN-rail mount
• FC-PBUS-0001: PROFIBUS DP adapter, master/slave configurable, up to 12 Mbps

Power Supply Modules

• FC-PSU-0001: HC900 24 VDC power supply, 5A, DIN-rail, input 85–264 VAC
• FC-PSU-0002: HC900 redundant power supply module, hot-swap capable, N+1 configuration

Sourcing Hard-to-Find & Obsolete HC900 Parts

The HC900 series has entered the mature-to-declining phase of its product lifecycle. Honeywell has progressively migrated customers toward the Experion PKS and Safety Manager platforms. As a result, several HC900 modules — including early-revision chassis, legacy CPU variants, and first-generation I/O modules — are no longer manufactured and have been removed from Honeywell's active price list.

Quality Control for the HC900 Range

HC900 I/O chassis and backplane modules present specific test challenges due to their multi-slot bus architecture and redundancy switching logic. DriveKNMS applies a structured test protocol for all HC900 chassis units prior to shipment:

• Visual inspection of backplane connector pins for oxidation, mechanical deformation, and PCB trace integrity
• Powered bus continuity test across all 12 slot positions using a calibrated bus analyzer
• Redundancy switchover simulation: primary-to-secondary bus failover is triggered and response time is measured against Honeywell specification (≤100ms)
• Thermal cycling: units are operated at 55°C for 4 hours to screen for latent thermal failures
• Firmware compatibility verification: chassis revision is cross-checked against the target CPU firmware version to confirm bus protocol compatibility
• Final functional test with a live HC900 CPU module installed, confirming I/O scan cycle integrity across all populated slots