Honeywell 10105/2/1 FSC Fail-Safe High-Density Analog Input Module

Description

Designed for high-integrity safety instrumented systems (SIS), the Honeywell 10105/2/1 functions as a high-density, fail-safe analog input module within the Fail-Safe Control (FSC) system architecture. This module processes up to 16 safety-critical analog channels operating on a nominal 24 Vdc field supply. To interface with standard industrial transmitters, the high-impedance inputs require external current-to-voltage conversion from 0-20 mA to the module's native 0 to 4.1 V range. This conversion is handled seamlessly through dedicated field termination assemblies or backplane conversion units, maintaining complete galvanic separation and safety loop integrity.

Key Technical Features

• High-Density Architecture: 16 independent analog input channels in a compact 4 TE width footprint.
• Safety-Certified Design: Meets safety requirements up to AK1-6 (configured up to AK6 in redundant configurations).
• High-Resolution Digitization: Integrated 12-bit A/D converter ensuring ±1 LSB accuracy.
• Flexible Signal Conversion: Compatible with FTA-T-14 field termination blocks or plug-in 10105/A/1 conversion modules.
• Low Power Consumption: Consumes only 35 mA from the 5 Vdc internal rail and 35 mA from the 24 Vdc system rail.

Industrial Applications

• Emergency Shutdown (ESD) systems in petrochemical processing facilities.
• Burner Management Systems (BMS) in heavy power generation plants.
• Fire and Gas (F&G) detection loops requiring high availability and low error rates.
• Critical loop monitoring in hazardous chemical reactors.

Technical Specifications

Signal Interface Architecture

Empirical Engineering Insights

Alternative Models & Compatibility

The module requires FSC system software version 500 or higher. Running earlier firmware platforms with this specific physical hardware profile can prevent diagnostic synchronization and fail to initialize safety states. Ensure that the corresponding conversion hardware (such as 10105/A/1) is aligned with the rack assembly before applying power.

Application Pitfalls & Engineering Notes

Because this is a high-impedance (> 1 MOhm) module, attempting to connect a standard raw 4-20 mA transmitter loop directly to the input pins without a conversion assembly (either the FTA-T-14 or 10105/A/1) will cause the input channel to saturate and trigger an open-loop system fault. System designers must ensure that the precision dropping resistors are correctly configured to scale the current signal to the 0 to 4.1 Vdc limits.

Commissioning & Wiring Tips

To guarantee that crosstalk remains above the specified 60 dB limit under noisy conditions, ensure that all field wiring routed from the process transmitters to the FTA module is constructed with high-quality twisted, individually shielded pairs. Connect the cable shields strictly at the instrument side or the safety-earth terminal block on the panel, but never at both ends, to avoid establishing ground loops.

Installation Guidelines