Key benefits and features of the Triconex Triple Modular Redundant (TMR) approach are:
- No single point of failure - The failure of any single component will not affect the
correct operation of the Tricon system.
- Very high safety integrity - With its TMR architecture and
high diagnostic coverage, the Tricon system achieves Safety Integrity
Level 3 as defined in the IEC 61508 Draft Standard on Functional Safety.
Tricon systems are also certified by TÜV for safety related operation
in applications requiring the German Safety Requirement Class 5 and
6.
- High availability - The Tricon TMR system can operate with one, two
of three functional Main Processors. Faulted modules can be replaced
while the system is operational for continuous uninterrupted control.
A typical system has an MTTFspurious of greater than 200 years using
the MIL-STD failure rates defined in the IEC 61508 Draft Standard.
Using actual failure rates based on 1994 Triconex field repair records,
the MTTFspurious of a typical system exceeds 1,000 years.
- Low maintenance costs - Highly skilled technicians are not required because extensive
built-in diagnostics automatically pinpoint faults to field replaceable modules.
- Transparent triplication - The Tricon TMR system has three
isolated, parallel control systems integrated into one set of hardware.
Two-out-of-three (2oo3) voting provides high integrity, error-free,
uninterrupted process operation. The Tricon appears to the user as
one set of hardware, not three, allowing one control program for the
application logic to be developed and downloaded to the three Main
Processors. Field sensors connect to input points on the field termination
panels. These signals are then separated into three isolated paths
on the input modules and the data is sent over separate communication
paths to the three Main Processors. After the control logic has been
executed, output modules perform a 2oo3 vote of the output data received
from the three Main Processors and send the result to the output termination
panels and the final field elements.
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