4

Voting for One Discrete Input

One input may be present in a non-voted input group, in a Simplex input group, in a Duplex input group where one input has failed, or in a Triplex input group where two inputs have failed.

In a non-voted input group, the actual input is always provided to the application logic.

In a voted input group, if only one input is available the result of the voting depends on the Voting Adaptation mode that has been configured for the input group.

Discrete Input Voting with One Input Present and Voting Adaptation Set to 3±2±1±0

For a Simplex Input group (one input) the voted input is the same as the actual input. This is also true if there is just one actual input present on a Duplex or Triplex group configured for 3±2±1±0 Voting Adaptation.

 

 

Field Input Data

Input Provided

 

 

 

 

 

 

 

 

Input A

0

 

 

to Application

 

 

 

 

Field Input

 

 

 

 

 

 

Logic

 

 

 

 

 

 

 

 

 

 

 

 

 

Data

 

Input B

0

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Input C

1

 

 

GMR Software Performs

 

 

 

 

 

 

 

 

 

 

1 out of 1 Voting if Voting

 

 

 

 

 

 

Adaptation is 3±2±1±0

 

Duplex State

0

 

 

Default State

1

Discrete Input Voting with One Input Present and Voting Adaptation Set to 3±2±0

Configuring a Duplex or Triplex input group for 3±2±0 Voting Adaptation prevents the data from just one input being used as the only input data for that group. If a Duplex or Triplex group configured for 3±2±0 Voting Adaptation has just one input present, the configured input Default State is used instead of the remaining actual input.

Field Input

Data

Field Input Data

Input Provided

 

 

 

Input A

0

 

to Application

 

 

 

 

Logic

 

 

 

 

 

 

 

 

 

Input B

0

 

 

1

 

 

 

 

 

 

 

 

 

Input C

1

 

GMR Software uses Default State

 

 

 

if Voting Adaptation is 3±2±0

Duplex State

0

Default State

1

GFK-0787B

Chapter 4 PLC Subsystem

4-11

Page 49
Image 49
GE GFK-0787B user manual Voting for One Discrete Input