Product Core Brief
- Model: AAI835-H50/K4A00
- Brand: YOKOGAWA
- Series: CENTUM VP / CS 3000 Analog I/O
- Core Function: 4-channel isolated 4–20 mA analog input/output module with HART communication for CENTUM VP/CS 3000 FCS.
- Product Type: DCS Analog I/O Module (4 AI + 4 AO)
- Key Specs: 4 isolated input/output channels | 4–20 mA DC | HART protocol | /K4A00 KS cable adapter
- Condition: New Original (New Surplus) / Factory Sealed
Product Introduction
Mixed analog I/O slots are where procurement mistakes get expensive. The / is a YOKOGAWA CENTUM VP/CS 3000 analog I/O module providing four 4–20 mA inputs and four 4–20 mA outputs on a single card, with channel isolation and HART protocol support. It is non-explosion-proof and ships with the /K4A00 KS cable interface adapter for the ATK4A-00 terminal board.
For maintenance teams, this module consolidates analog I/O density while keeping input and output loops electrically separated. HART communication allows smart transmitter and positioner diagnostics without adding a separate communicator. That reduces spare-part variety, shortens replacement time, and helps avoid wiring confusion during shutdowns.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Full Model | / |
| Product Type | Analog I/O Module (AI + AO) |
| Compatible System | YOKOGAWA CENTUM VP / CS 3000 DCS |
| Signal Range | 4–20 mA DC |
| Channel Configuration | 4 analog inputs + 4 analog outputs |
| Isolation | Channel-isolated |
| Digital Communication | HART protocol |
| Explosion Protection | Non-explosion-proof (-5) |
| Option Code | /K4A00 — KS cable interface adapter for ATK4A-00 |
| Redundancy | Supported in dual redundant configuration per product family specification |
| Typical Application | Process control loops requiring both analog input and output with smart device diagnostics |
Key Selling Points & Differentiators
- 4 AI + 4 AO on one card: Reduces slot usage and simplifies spare-parts management compared with separate input and output modules.
- HART-enabled channels: Supports smart device diagnostics over the 4–20 mA loop for both input and output sides.
- Channel isolation: Helps limit ground loops and cross-channel interference in mixed-signal racks.
- Correct terminal interface: The option matches the ATK4A-00 KS cable adapter, reducing wiring rework during replacement.
- Direct CENTUM VP/CS 3000 fit: Designed for YOKOGAWA FCS racks, making it a practical OEM replacement for maintenance or spares.
- Not recommended for: Pure analog input or pure analog output replacements, 1–5 V DC or ±10 V signals, explosion-proof zones, or systems requiring AAI135/AAI141/AAI543 channel counts. Always verify the exact option code before ordering.
Quality Transparency SOP
Mixed analog I/O modules need separate verification for input and output behavior.
- Incoming visual QA: Inspect factory sealing, label integrity, connector pins, PCB condition, and corrosion indicators.
- Isolation verification: Use a Fluke multimeter or insulation tester to confirm channel-to-channel and channel-to-ground isolation.
- Input channel verification: Apply a calibrated 4–20 mA source and confirm input response, offset, and linearity.
- Output channel verification: Drive each output into a calibrated load and verify 4 mA, 12 mA, and 20 mA setpoints.
- HART communication check: Verify HART recognition on at least one input and one output channel using a HART communicator or simulator.
- 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 the ATK4A-00 terminal board. Using the wrong adapter can create wiring mismatches.
Do not substitute for AAI135, AAI141, AAI143, or AAI543. The AAI835-H50 is a mixed 4 AI + 4 AO module. Replacing a dedicated input or output card with this module will not match channel assignments.
Verify HART loop impedance. HART communication requires adequate loop resistance. Too low a load can cause unstable device communication on both input and output channels.
Check FCS slot and engineering configuration. Confirm tag mapping, I/O assignment, HART enablement, and redundancy settings in the CENTUM VP/CS 3000 project before inserting the module into a live rack.
Buyer’s FAQ
Is this module genuine YOKOGAWA?
Yes. The / is an OEM YOKOGAWA CENTUM VP/CS 3000 analog I/O 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 ATK4A-00 terminal board. This is critical for field wiring compatibility.
Does it support HART?
Yes. The -H50 suffix indicates HART protocol support on a 4-channel input/4-channel output, 4–20 mA isolated analog I/O module.
Can I replace an AAI135 or AAI543 with this module?
No. The AAI835-H50 provides both analog inputs and analog outputs on one card. AAI135 is an 8-channel analog input module, and AAI543 is a 16-channel analog output module. Substitution requires engineering approval.
What is the warranty and lead time?
Each module carries a standard 12-month functional warranty from shipment, excluding damage from incorrect installation, overloading, or mismatched terminal adapters. In-stock units typically ship within 1–3 business days after payment confirmation.
