GE GFK-0787B Noise Reduction Machine User Manual


 
4
4-8 Genius Modular Redundancy Flexible Triple Modular Redundant (TMR) System
User’s Manual – March 1995
GFK-0787B
Discrete Input Voting
Immediately after the input scan, before the application program execution begins, the
GMR software performs input voting. It automatically reads and votes on the three (or
two) sets of data in areas A, B, and C of the discrete Input Table.
If a failure (discrepancy fault, Autotest fault, or Genius fault) occurs, the GMR software
adapts to reject the faulty data. Depending on the configuration of the input group,
input voting may adapt from three inputs to two inputs to one input, or from three
inputs to two inputs to the configured default state.
Field Input
Data
Input A
Input B
Input C
0
1
1
1
Single Input Provided
to Application Logic
Duplex State
1
Default State
0
In addition to field input data, the GMR software may also make use of the input
group’s configured Duplex State and Default State in determining the final input value
to provide to the PLC.
The Duplex State is a “tiebreaker” value used when there are two field
inputs operating. Its operation is described on page 4-10.
The Default State is the value that will be provided directly to the PLC
instead of a voted input value if the following inputs fail:
The single input in a Simplex group.
The remaining input in a Duplex or Triplex group configured for
3–2–1–0 Voting Adaptation.
Either of the two inputs to a Duplex group configured for 3–2–0
Voting Adaptation.
Either of the two remaining inputs to a Triplex group configured for
3–2–0 Voting Adaptation.
Duplex State
Default State