Triple Modular Redundancy

Special high rehabiUty systems have been developed for safety shutdowns, eg, triple modular redundant systems (TMRS), which are designed to be... 

Fig. 5. Stmcture of a triple modular redundant system (TMRS). See text.

Triple Modular Redundant (TMR) - A system that employs a 2 out of 3 (2003), voting scheme to determine the appropriate output action. It is based on the application of three separate operating systems running in parallel. 

Such results show that software-based techniques combined with HETA can be used in harsh environments and allow designers to reach fast fault diagnosis and correction. When comparing to hardware-based techniques, such as Xilinx Triple Modular Redundancy (XTMR) with scmbbing, that require modifications to the microprocessor s hardware, we can notice an area reduction higher than 66% and still acceptable fault coverage of 96.9%. On the other hand, the hardened application takes 1.48 times the original time to execute and 6.5 % more area to implement the OCFCM hardware module. 

KASTENSMIDT, E STERPONE, L. CARRO, L. SONZA REORDA, M. On the optimal design of triple modular redundancy logic for SRAM-based FPGAs. In DESIGN, AUTOMATION AND TEST IN EUROPE CONFERENCE, 2005, DATE 2005. Proceedings... New York, USA ACM Press, 2005, pp. 1290-1295. 

A means by which an approach by an individual beyond the safe limit of working machinery causes the device to activate and stop the machine or reverse its motion. Triple Modular Redundant (TMR) ESD System... 

The minimum size of the self-assembling ALU is a factor of a hundred times greater than that of a single ALU and over thirty times that of a triple modular redundant ALU. 

In instrumentation and control, triple modular redundancy is very important for fail safe operation. Fig. 1/6.1.2-1 shows the same. Here, each of the three elements are voted thrice in each stage to get the output. In network communications, especially for remote communication, there are a few other problems known as Two Army problem, Byzantine general problem, etc. The issues discussed so far basically belong to fault masking to get away with hardware fault. There is another term called dynamic recovery, in which case there shall be a special mechanism to detect hardware fault and isolate the faulty hardware and replace the same with a good one. This wiU be clear from an example. Say in a process control, there are two processors one working and the other standby. If there is another processor whose main function is to act a diagnostic processor to check health of other processors, when it finds fault with... 

B) typical 2oo3 architectural block diagram, and (C) triple modular redundancy (Typical). 

The most popular configuration in safety applications is the triple modular redundant... 

Fault tolerance is achieved through triple modular redundancy (TMR)... 

Triple modular redundancy (TMR) logic for critical controls measurements... 

Invensys-Schneider Tricon uses triple modular redundant (TMR) architecture in which three parallel control paths are integrated into a single overall system. This gives high fault tolerance, with no process-controlled interrupts and extensive self-test and diagnostics. 

HIPS) or triple modular redundant (TMR) arrangements. The numbers are summarized in Table 10.2. 

Another option might have been the implementation of a triple modular redundant [4] (TMR, fault masking structural redundancy) system with robust majority voting schemes at the actuators. Such systems can be built either with synchronously running processor units and distributed local code/data memories, or asynchronously running processor units with local access to code and shared access to triple redundant data memories. The complexity and hardware demand of such a system architecture is so high, however, that this idea had to be rejected for technical reasons (mass, volume, harness, power consumption, etc.). 

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