Description
Product Overview
YOKOGAWA AAI135-H50/K4A00 is an Analog Input Module (Current Input) designed for the Yokogawa CENTUM VP / CS 3000 and ProSafe-RS safety control systems. It provides 8-channel isolated 4–20 mA analog input acquisition with HART digital communication support for intelligent field transmitters.
The module is part of Yokogawa’s AAI135 series analog input modules, designed for high-reliability process automation applications. The isolated input channels allow connection of multiple transmitters while reducing interference between field signals. The /K4A00 option specifies the inclusion of a KS Cable Interface Adapter (ATK4A-00) for system connection.
The AAI135-H50/K4A00 is widely used in industries requiring precise analog measurement and intelligent device diagnostics, including oil & gas, chemical processing, power generation, and safety instrumented systems.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Yokogawa |
| Model | AAI135-H50/K4A00 |
| Product Type | Analog Input Module |
| Series | AAI135 |
| Input Channels | 8 channels |
| Input Type | 4–20 mA DC |
| Channel Type | Isolated input channels |
| HART Communication | Supported |
| Explosion Protection | Non-explosion protected type |
| Input Current Range | 4–20 mA |
| Maximum Allowable Input Current | 25 mA |
| Input Resistance | 290 Ω (20 mA) to 450 Ω (4 mA) |
| Power OFF Resistance | ≥500 kΩ |
| Accuracy | ±16 μA |
| Data Update Period | 10 ms |
| Isolation Voltage | 500 VAC for 1 minute |
| Transmitter Power Supply | ≥15.0 V at 20 mA |
| Operating Temperature | Approx. -20 to +70 °C |
| Power Consumption | 360 mA (5 VDC), 450 mA (24 VDC) |
| Weight | Approx. 0.3 kg |
| External Interface | KS Cable Interface Adapter ATK4A-00 |
Main Features and Advantages
8-Channel Isolated Analog Input
The AAI135-H50/K4A00 provides eight independent analog input channels for connecting field transmitters.
Typical input devices:
- Pressure transmitters
- Flow transmitters
- Temperature transmitters
- Level transmitters
- Analyzer transmitters
Channel isolation improves:
- Signal stability
- Noise immunity
- System reliability
- Field wiring flexibility
AAI135-H50
HART Communication Support
The built-in HART capability enables communication with smart field instruments while maintaining the standard 4–20 mA measurement loop.
HART functions include:
- Device identification
- Transmitter diagnostics
- Configuration access
- Instrument status monitoring
- Maintenance information retrieval
High Measurement Accuracy
The module provides accurate analog conversion with:
- ±16 μA input accuracy
- Fast 10 ms update cycle
- Stable signal processing
This makes it suitable for demanding process control loops requiring reliable measurement.
Electrical Isolation Protection
Each input channel is isolated to reduce the impact of:
- Ground loops
- Electrical noise
- Field interference
- Potential differences between instruments
Isolation rating:
- 500 VAC for 1 minute between input and system
- 500 VAC for 1 minute between input channels
Applications
Process Control Systems
Common applications:
- Continuous process monitoring
- Closed-loop control
- Alarm monitoring
- Regulatory control loops
Oil & Gas Industry
Used for:
- Pipeline monitoring
- Refinery instrumentation
- Compressor stations
- Offshore platforms
Chemical and Petrochemical Plants
Typical measurements:
- Reactor pressure
- Tank level
- Flow rate
- Temperature monitoring
Power Generation
Applications include:
- Boiler instrumentation
- Turbine auxiliary monitoring
- Generator systems
- Balance-of-plant control
Safety Instrumented Systems
The module can be applied in Yokogawa safety-related architectures where reliable analog measurement and HART diagnostics are required.
Related Products
- YOKOGAWA AAI135-H00/K4A00 — Similar 4–20 mA analog input module with HART communication.
- YOKOGAWA AAI141 — Analog input module series for voltage/current signals.
- YOKOGAWA AAI143 — Analog input module for process control applications.
- YOKOGAWA AAI543 — Analog output module.
- YOKOGAWA AAT145 — Temperature input module.
- YOKOGAWA ProSafe-RS — Safety instrumented system platform.
