3603E Triconex Digital Output Module TMR Architecture

3603E Invensys Triconex Digital Output Modules

Product Details:

Description:

A TMR digital output (DO) module receives output signals from the main processors on each of three channels.

Each set of three signals is then voted by special quadruplicated output circuitry on the module. The circuitry produces one voted output signal and passes it to the field termination. The quadruplicated voter circuitry provides multiple redundancy for all critical signal paths, guaranteeing safety and maximum availability.

Each TMR digital output module has a voltage-loopback circuit which verifies the operation of each output switch independently of the presence of a load and determines whether latent faults exist. Failure of the detected field voltage to match the commanded state of the output point activates the LOAD/FUSE alarm indicator.

In addition, ongoing diagnostics are performed on each channel and circuit of a TMR digital output module.

Failure of any diagnostic on any channel activates the Fault indicator, which in turn activates the chassis alarm signal. The Fault indicator merely indicates a channel fault, not a module failure. The module is guaranteed to operate properly in the presence of a single fault and may continue to
operate properly with certain kinds of multiple faults.