TRICONEX AI3351S2 Analog Input PLC Module

"AI": Function code, which stands for "Analog Input". It clearly defines the core function of the module as collecting analog signals, distinguishing it from "DI (Digital Input)", "DO (Digital Output)", and "AO (Analog Output)" modules.

"3351": Series number, representing the third-generation analog input module platform of TRICONEX. It has optimized signal sampling accuracy, anti-interference capability, and redundancy compatibility. Compared with the previous-generation AI3301 module, its sampling rate is increased by 30%, and it supports expanded signal types.

"S2": Hardware version and safety level identifier. The "S" stands for "Safety", indicating that the module is compatible with SIL 3 safety loops. The "2" represents the second-generation hardware version, which has optimized power management and diagnostic algorithms, and is compatible with TRICONEX system firmware V11.3 and above.

Power status light (PWR): Green indicates normal power supply, red indicates power failure, and yellow indicates standby power switching.

Operation status light (RUN): Green indicates normal signal acquisition, blinking green indicates signal calibration in progress, and red indicates module failure.

Redundancy status light (RED): Green indicates normal redundancy synchronization, yellow indicates redundancy switching in progress, and red indicates redundancy failure.

There are also 4 channel status lights (CH1~CH4): Green indicates normal single-channel acquisition, and red indicates channel failure (e.g., signal over-range).

The signal input end is equipped with 16 Phoenix terminals (divided into 4 groups, 4 channels per group, supporting differential input), which can be adapted to 2-wire or 4-wire sensors.

The power supply end is provided with 2 24V DC input terminals (with reverse connection protection and supporting redundant power supply).

The redundancy synchronization interface is a 1-channel RJ45, used for data synchronization with redundant modules, with a communication rate of 100Mbps.

There is also a 1-channel USB Type-C calibration interface, which can be directly connected to calibration equipment for on-site signal calibration without disassembling the module.

Each catalytic cracking unit is configured with 2 TRICON 5130 controllers, each paired with 2 AI3351S2 modules (1+1 redundancy). The 16 channels collect signals from 8 key sensors (each sensor with 2-channel cross-validation) to ensure acquisition accuracy.

Modules transmit data to controllers via TRICON's proprietary bus. Controllers execute interlock logic and immediately trigger ESD actions upon detecting parameter overruns. Real-time data is simultaneously uploaded to the MES system via OPC UA protocol for production process monitoring.

Benefiting from AI3351S2's wide temperature design and corrosion-resistant housing, modules can be directly installed in cabinets near the unit without additional temperature and moisture control measures, reducing deployment costs.

Each wellhead is equipped with 1 TRICON 4100 controller and 2 AI3351S2 modules (redundant configuration). The 16 channels cover 10 monitoring points (including 2 standby channels). Modules feature IP65 front panel protection to resist wellhead dust and water spray.

The module's built-in vibration resistance design (compliant with IEC 60068-2-6 standard) withstands mechanical vibrations during wellhead extraction, preventing data fluctuations. Data is transmitted to the local wellhead HMI via Modbus RTU protocol for real-time viewing by on-site personnel.

Redundant modules achieve synchronization cycles ≤1ms. Even if the main module fails due to environmental interference, the backup module switches seamlessly, ensuring uninterrupted pressure monitoring and preventing safety accidents from wellhead overpressure.

The boiler control system is configured with 1 TRICON 5000 controller and 1 AI3351S2 module. 10 of the 16 channels collect key parameters (including 3 redundant water level signal acquisitions), with the remaining 6 channels as standby.

The module utilizes 24-bit Delta-Sigma ADC and differential input design with common-mode rejection ratio ≥100dB, enabling it to resist electromagnetic interference from power plant generators and transformers while ensuring water level signal acquisition accuracy.