GE Mark VIe System Manual page 44

TMR Fanned – Three I/O Packs with One IONet per I/O Pack
TMR Dedicated – Three simplex I/O modules with One IONet per I/O Pack
For any of the above input configurations, multiple inputs can be used to provide application redundancy. For example, three
Simplex inputs can be used and selected in application code to provide sensor redundancy.
The Mark VIe control provides configuration capability for input selection and voting using a simple, highly reliable and
efficient selection/voting/fault detection algorithm to reduce application configuration effort. This maximizes the reliability
options for a given set of sensor inputs and provides output voting hardware compatibility. All applicable subsets of reliability
options are available on a per terminal board basis for any given Mark VIe topology. For example, in a TMR controller, all
simplex and dual option capabilities are also provided.
While each IONet is associated with a specific controller that is responsible for transmitting outputs, all controllers see all
IONets. The result is that for a simplex input the data is not only seen by the output owner of the IONet, it is seen in parallel
by any other controllers. The benefit of this is that loss of a controller associated with a simplex input does NOT result in the
loss of that data. The simplex data continues to arrive at other controllers in the system.
A single input can be brought to the three controllers without any voting. This is used for non-critical, generic I/O, such as
monitoring 0-20 mA inputs, contacts, thermocouples, and resistance temperature devices (RTD). This interconnection can
also include the following gateway devices: CANbus, F ® , Profibus, and Modbus.
Fieldbus
OUNDATION
Single Input to Three Controllers, Not Voted
One sensor can be fanned to three I/O boards as above for medium-integrity applications. This is used for sensors with
medium-to-high reliability. Three such circuits are needed for three sensors. Typical inputs are 0-20 mA inputs, contacts,
thermocouples, and RTDs.
44 GEH-6721_Vol_I_BP GEH-6721_Vol_I Mark VIe and Mark VIeS Control Systems Volume I
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