Product Core Brief
- Model: YOKOGAWA AAI841-H50/K4A00
- Brand: YOKOGAWA
- Series: CENTUM CS 3000 / AAI841 Analog I/O Series
- Core Function: Provides 8 analog inputs and 8 analog outputs in 4–20 mA with HART communication for CENTUM CS 3000 DCS.
- Product Type: DCS Analog Input/Output Module
- Key Specs: 4–20 mA AI/AO | 8 AI + 8 AO | HART protocol | non-isolated | KS cable interface
- Condition: New Original (New Surplus) / Factory Sealed
Product Introduction
Mixed analog I/O cards are often the hardest to replace quickly because they combine input and output channels in one slot. The YOKOGAWA AAI841-H50/K4A00 is an 8-channel analog input and 8-channel analog output module for CENTUM CS 3000 DCS, handling 4–20 mA signals with HART digital communication on applicable channels.
The “-H” suffix confirms HART protocol support; “50” indicates no explosion protection with basic type; and “/K4A00” means it is supplied with the KS cable interface adapter ATK4A-00 for connection to the terminal board. This module is non-isolated, so loop grounding and wiring discipline matter more than on isolated cards. For systems that already use AAI841-H50 slots, keeping one matched spare avoids re-engineering terminal wiring during an emergency swap.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Model | AWA 0 |
| Product Type | Analog Input/Output Module (DCS) |
| Compatible System | CENTUM CS 3000 series |
| Signal Range | 4–20 mA input and 4–20 mA output |
| Channels | 8 analog inputs + 8 analog outputs |
| HART Communication | Supported |
| Isolation | Non-isolated |
| Explosion Protection | No explosion protection |
| Interface Option | /K4A00 — KS cable interface adapter ATK4A-00 |
| Typical Application | Mixed AI/AO slots where HART access is required |
Key Selling Points & Differentiators
- Combines 8 AI and 8 AO channels in one CENTUM CS 3000 slot, saving backplane space.
- HART communication enables smart device diagnostics and configuration.
- Supplied with /K4A00 KS cable interface adapter for direct connection to compatible terminal boards.
- Direct replacement for existing AAI841-H50/K4A00 installations.
- Factory-sealed surplus inventory with visual QA and 12-month warranty.
- Not recommended for applications requiring channel-to-channel isolation; consider isolated AI and AO modules such as AAI143 and AAI543 instead.
Quality Transparency SOP
- Visual inspection: Verify label, suffix “-H50,” option “/K4A00,” connector pins, and housing for moisture, corrosion, or handling damage.
- Seal verification: Confirm original anti-static bag, desiccant, and factory labeling before opening.
- Backplane power check: Verify 5 VDC and 24 VDC rails before insertion; mixed I/O modules can draw more current than single-function cards.
- AI channel test: Use a precision current source and Fluke multimeter to verify 4 mA, 12 mA, and 20 mA readings on multiple input channels.
- AO channel test: Measure 4 mA, 12 mA, and 20 mA outputs under known load and confirm HART communication with a HART communicator.
- Interface check: Confirm the KS cable interface adapter mates correctly with the terminal board and that pin assignments match the existing loop wiring.
Technical Risk Avoidance
❗ Confirm the /K4A00 interface before ordering. This variant uses the KS cable interface adapter ATK4A-00; it may not match systems wired for /A4S00, /A4D00, or /CCC01 terminals.
❗ This module is non-isolated. Ground loops, improper shielding, or incorrect transmitter wiring can cause measurement errors or output instability.
❗ Check HART channel allocation. Not every channel may support HART simultaneously depending on system configuration and firmware; verify against your CENTUM CS 3000 engineering data.
❗ Verify backplane current capacity. Mixed 8+8 channel I/O modules can load the node supply more heavily than single-function cards.
Buyer’s FAQ
Is the YOKOGAWA AAI841-H50/K4A00 a genuine OEM part?
Yes. It is an original Yokogawa AAI841 series analog I/O module supplied as new surplus, factory sealed when available. We do not rebrand or relabel third-party substitutes.
What does “/K4A00” mean?
It indicates the module is supplied with the KS cable interface adapter, model ATK4A-00, for connection to the terminal board. If your existing wiring uses pressure-clamp terminals or MIL connectors, this option may not match.
Is this module isolated?
No. The AAI841 family is specified as non-isolated for this configuration. If isolation is required, consider separate isolated AI and AO modules.
Can I replace an AAI841-S50/K4A00 with this module?
Only if HART communication is required and your system configuration supports it. The -H50 adds HART capability; the -S50 does not.
What warranty do you offer?
A 12-month warranty against manufacturing defects and DOA issues. Damage from incorrect wiring, overvoltage, backplane faults, or mismatched terminal interface is not covered.
