Triconex by Schneider Electric Tricon™ v9–v11 Systems

Controller Features

The Tricon controller is a state-of-the-art programmable logic and process controller that

provides a high level of system fault tolerance. To ensure the highest possible system integrity

at all times, the Tricon controller includes these features:

• Provides Triple Modular Redundant (TMR) architecture whereby each of three

identical system channels independently executes the control program, and specialized

hardware/software mechanisms “vote” all inputs and outputs.

• Withstands harsh industrial environments.

• Enables field installation and repair to be done at the module level while the controller

remains online. Replacing an I/O module does not disturb field wiring.

• Supports up to 118 I/O modules (analog and digital) and optional communication

modules that interface with Modbus masters and slaves, Foxboro® and Honeywell™

Distributed Control Systems (DCS), other Triconex controllers in Peer-to-Peer

networks, and external host applications on Ethernet networks.

• Provides integral support for remote I/O modules located as far away as 7.5 miles

(12 kilometers) from the Main Chassis, using SRXM modules.

• Executes control programs developed and debugged with TriStation™ 1131

Developer’s Workbench Software or TriStation MSW software.

• Provides intelligence in the input and output modules to reduce the workload of the

Main Processors. Each I/O module has three microprocessors. Input module

microprocessors filter and debounce the inputs and diagnose hardware faults on the

module. Output module microprocessors supply information for the voting of output

data, check loopback data from the output terminal for final validation of the output

state, and diagnose field-wiring problems.

• Provides integral online diagnostics with adaptive-repair capabilities.

• Allows normal maintenance while the Tricon controller is operating, without

disturbing the controlled process.

• Supports transition to a hot-spare I/O module for critical applications where prompt

service may not be possible.

Fault Tolerance

Fault tolerance, the most important capability of the Tricon controller, is the ability to detect

transient and steady-state error conditions and to take appropriate corrective action online.

With fault tolerance, there is an increase in safety and an increase in the availability of the

controller and the process being controlled.

The Tricon controller provides fault tolerance through Triple Modular Redundant (TMR)

architecture. The controller consists of three identical system channels, except for the Power

Modules which are dual-redundant. Each channel independently executes the control program

(also referred to as the TriStation application) in parallel with the other two channels. Hardware

voting mechanisms qualify and verify all digital inputs and outputs from the field; 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 occurs in one channel, the faulty channel is overridden by the

other channels. Repairs consist of removing and replacing the failed module in the faulty

channel while the Tricon controller is online and without process interruption. The controller

then reconfigures itself to full TMR operation.

Extensive diagnostics on each channel, module, and functional circuit immediately detect and

report operational faults by means of indicators or alarms. The diagnostics also store

information about faults in system variables. If faults are detected, the operator can use the

diagnostic information to modify control actions or direct maintenance procedures.

Because the triplicated system operates as one control system, the Tricon controller can be

programmed with one control program that terminates sensors and actuators at a single wiring

terminal.

System Configuration

Physically, a basic Tricon controller consists of Main Processors and I/O modules,

communication modules, the chassis enclosing the modules, field wiring connections, and a

TriStation PC. This section briefly describes these components and provides general