Product Core Brief
- Model: AAI135-H50/K4A00
- Brand: YOKOGAWA
- Series: CENTUM VP Analog I/O
- Core Function: 8-channel isolated 4–20 mA analog input with HART digital communication for CENTUM VP FCS.
- Product Type: DCS Analog Input Module
- Key Specs: 8 isolated channels | 4–20 mA input | HART protocol | Non-explosion-proof | ATK4A-00 KS cable adapter
- Condition: New Original (New Surplus) / Factory Sealed
Product Introduction
Replacing a failed analog input card during a live run is never just about the part number. The / is built for CENTUM VP field control stations where 4–20 mA process signals must stay stable, isolated, and diagnosable. With HART communication enabled, it also supports smart transmitter diagnostics without adding a separate gateway.
This module matters most when unplanned I/O faults threaten loop integrity. Eight isolated channels help limit cross-channel interference, and the option means it ships ready for the AEA4D terminal board with ATK4A-00 KS cable interface. That reduces wiring rework and shortens swap-out time during maintenance windows.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Full Model | / |
| Product Type | Analog Input Module |
| Compatible System | YOKOGAWA CENTUM VP DCS |
| Signal Range | 4–20 mA |
| Channel Count | 8 channels |
| Isolation | Channel-isolated |
| Digital Communication | HART protocol |
| Explosion Protection | Non-explosion-proof (-5) |
| Option Code | /K4A00 — KS cable interface adapter for AEA4D terminal board (ATK4A-00) |
| Typical Application | Process temperature, pressure, flow, and level inputs |
Key Selling Points & Differentiators
- HART-enabled analog input: Reads 4–20 mA while retaining smart device diagnostics, reducing the need for extra communicators during troubleshooting.
- Channel-to-channel isolation: Helps prevent ground loops and limits fault propagation across loops.
- Correct terminal interface: The suffix matches AEA4D terminal boards via ATK4A-00, so field wiring stays consistent with existing drawings.
- Direct CENTUM VP fit: Designed for YOKOGAWA FCS racks, making it a practical OEM replacement for maintenance, upgrades, or spares provisioning.
- Not recommended for: 1–5 V DC analog inputs, 16-channel density needs, explosion-proof zones, or non-CENTUM VP platforms. For those cases, verify the exact AAI/AAV/AAI841 family match first.
Quality Transparency SOP
For surplus DCS I/O modules, verification should go beyond a visual check.
- Incoming visual QA: Inspect factory sealing, label integrity, PCB condition, connector pins, and corrosion indicators.
- Continuity and insulation check: Use a Fluke multimeter to verify terminal continuity and isolation between channels before power-up.
- Bench signal verification: Apply a calibrated 4–20 mA source and confirm channel response, offset, and linearity across the span.
- HART communication check: Verify that the module can recognize and communicate with a HART transmitter or simulator on at least one channel.
- Final packing: Record serial/lot information, apply anti-static packaging, and seal with a condition label.
Technical Risk Avoidance
❗ Confirm the /K4A00 terminal match. This variant uses the KS cable interface for AEA4D terminal boards. Using the wrong terminal adapter can cause wiring mismatches.
❗ Check FCS slot and power budget. CENTUM VP I/O nodes have backplane and power constraints; verify the slot assignment and node loading before hot insertion.
❗ Verify HART addressing. If smart transmitters are multidrop or using device variables, confirm tag mapping and polling configuration in the engineering station before commissioning.
❗ Protect signal wiring. Keep 4–20 mA loops away from VFD cables and high-current feeders. Use shielded cable and proper grounding to avoid noise on isolated channels.
Buyer’s FAQ
Is this module genuine YOKOGAWA?
Yes. The / is an OEM YOKOGAWA CENTUM VP analog input module. We supply it as new original/new surplus unless otherwise stated.
What does /K4A00 mean?
It indicates the KS cable interface adapter for the AEA4D terminal board, model ATK4A-00. This matters for field wiring compatibility.
Can I replace an AAI135-S50 with this H50 version?
Not automatically. The H50 adds HART communication. The mechanical fit may be similar, but engineering configuration, device tags, and diagnostics must be verified in the CENTUM VP project.
Do you offer a warranty?
Yes. Each module is covered by a standard 12-month functional warranty from shipment, excluding damage from incorrect installation, power surges, or mismatched terminal adapters.
What is the lead time?
If the unit is in stock, it can ship within 1–3 business days after payment confirmation. For larger quantities or specific batch requests, confirm availability before ordering.
