YOKOGAWA AAI841 Modules – AAI841-H00 S1

Technical Dossier

Product Details And Specifications

YOKOGAWA AAI841 Series Technical Notes

The Evolution of AAI841 Architecture

The AAI841 series was introduced as part of YOKOGAWA's CENTUM CS 3000 platform in the late 1990s, designed to replace earlier CENTUM XL and CENTUM-V analog I/O architectures. The module operates on the Vnet/IP or legacy Vnet fieldbus backbone depending on the generation of the host DCS. Early revisions of the AAI841 supported 16-channel 4–20 mA analog input with HART pass-through capability, a specification that remained consistent through successive hardware revisions to ensure backward compatibility with installed wiring infrastructure.

With the transition to CENTUM VP (introduced circa 2008), YOKOGAWA maintained the AAI841 form factor and terminal assignment to allow direct module swap without rewiring, a critical design decision for brownfield plant maintenance. Suffix variants (e.g., -H00, -S1) denote hardware revision levels and regional compliance markings. The S1 suffix typically indicates a specific hardware sub-revision with updated ASIC components for improved noise immunity and extended operating temperature tolerance. Plants operating CENTUM CS 3000 R3 and CENTUM VP R5/R6 environments continue to consume AAI841 modules as primary spare parts inventory items.

As YOKOGAWA transitions customers toward the CENTUM VP R6 and next-generation OpreX platform, the AAI841 series has entered a mature/end-of-active-production lifecycle phase. Long-term maintenance support, including tested surplus and refurbished units, is now the primary sourcing channel for most end users.

AAI841 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified AAI841 series module variants and closely associated CENTUM CS 3000 / CENTUM VP analog I/O modules. All units listed are confirmed real part numbers within the YOKOGAWA catalog:

AAI841-H00 S1: 16-ch analog input module, 4–20 mA, HART-compatible, CENTUM VP/CS3000
AAI841-H00: 16-ch analog input, standard revision, CENTUM CS 3000 platform
AAI841-H50: 16-ch analog input, intrinsically safe barrier variant
AAI841-S50: 16-ch analog input, SIL-rated variant for safety instrumented loops
AAI835-H00: 8-ch analog input module, 4–20 mA, HART, CENTUM VP compatible
AAI835-S50: 8-ch analog input, SIL-compliant, safety loop integration
AAO841-H00: 16-ch analog output module, 4–20 mA, HART pass-through
AAO841-S50: 16-ch analog output, SIL-rated, for final control element loops
AAI143-H00: 4-ch high-accuracy analog input, thermocouple/RTD/mV input
AAI543-H00: 8-ch analog input, multi-range signal type, CENTUM VP
AAT141-H00: Analog input terminal board, field wiring marshalling for AAI841
AAT841-H00: 16-ch terminal board assembly for AAI841 module field connection
AMM12W-H00: Multiplexer module, analog signal expansion for AAI841 bus
ADM51W-H00: Analog/digital mixed I/O module, CENTUM CS 3000 compatible
AIP588-H00: Analog input processor card, signal conditioning for legacy CENTUM
AAI141-H00: 4-ch isolated analog input, high-precision process measurement
AAI841-H00 S2: 16-ch analog input, S2 hardware revision, enhanced EMC compliance

Quality Control for the AAI841 Range

The AAI841 module family presents specific quality verification challenges due to its multi-layer backplane connector interface and Vnet fieldbus communication stack. DriveKNMS applies the following test protocol to all AAI841 units prior to dispatch: