3700A Triconex Analog Input Module with 32 Differential Channels 12 Bits Resolution

1. Chassis

Structural backbone for all modules

Provides backplane connectivity and power distribution

2. Power Supply Modules

Redundant, stable power delivery

Supports uninterrupted system operation

3. Main Processors

Executes real-time control and logic

Fault-tolerant processing for critical operations

4. Communication Modules

High-speed, deterministic internal and external communication

Multi-protocol support for system integration

5. Fiber-Optic Remote Extender Modules (RXM)

Extends system reach to remote locations

Secure, long-distance data transmission

6. Interface Modules

Connects Tricon to field devices

Signal conversion and integration with plant equipment

7. I/O Modules

Handles analog and digital inputs/outputs

Ensures precise monitoring and control of process variables

Analog Input (AI) Modules consist of three independent input channels, each receiving variable voltage signals from field points. These signals are converted to digital values and transmitted to the three Main Processor modules on demand. In TMR mode, a mid value selection algorithm is used to choose one value, ensuring correct data for every scan. Sensing of each input point is designed to prevent a single channel failure from affecting the others.

Each Analog Input Module performs continuous diagnostics on all channels. Any diagnostic failure on a channel activates the module’s Fault indicator, which in turn triggers the chassis alarm signal. The Fault indicator reports only a channel fault rather than a module failure, allowing the module to continue operating with up to two faulty channels.

Analog Input Modules support hot-spare capability, enabling online replacement of a faulty module without system interruption. They require a separate external termination panel (ETP) with a cable interface to the Tricon backplane. Each module is mechanically keyed to ensure proper installation in a Tricon chassis.