Tricon System Introduction

The Tricon is a state-of-the art controller that provides fault tolerance by means of Triple-Modular Redundant (TMR) architecture. TMR integrates three isolated, parallel control systems and extensive diagnostics in one control system. The system uses two-out-ofthree voting to provide high-integrity, error-free, uninterrupted process operation with no single point of failure.

The Tricon controller uses three identical channels. Each channel independently executes the control program in parallel with the other two channels. Specialized hardware/software voting mechanisms qualify and verify all digital inputs and outputs from the field, while analog inputs are subject to a mid-value selection process. Because each channel is isolated from the others, no single-point failure in any channel can pass to another. If a hardware failure does occur on one channel, the other channels override it. Meanwhile the faulting module can easily be removed and replaced while thecontroller is online without interrupting the process. Setting up control programs is simplified with the triplicated Tricon system, because it operates as a single control system from the user’s point of view. The user terminates sensors and actuators at a single wiring terminal andprograms the Tricon with one set of control program logic.

The Tricon controller manages the rest! Extensive diagnostics on each channel, module, and functional circuit immediately detect and report operational faults by means of indicators or alarms.

Tricon System features  

All diagnostic fault information is accessible by the control program and the operator. The program or the operator can use diagnostic data to modify control actions or direct maintenance procedures. Other key features of the Tricon controller that ensure the highest possible system integrity are:

• No single point of failure

• Ability to operate with 3, 2 or 1 Main Processor before shutdown

• Fully implemented and transparent triplication

• Comprehensive system diagnostics

• Complete range of I/O modules

• Dual and single I/O modules for safety-critical points with a limited need for availability

• Remote I/O up to 7.5 miles (12 kilometers) away from MPs

• Simple, online module repair

• Unsurpassed reliability and availability