*
EICAS snapshots

*
Displays (exceedances, etc.)

*
Scheduled maintenance tasks.

The primary display function (PDF) sends the flight deck effects to the CMCF. The CMCF then correlates the FDE to a maintenance message.

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CMCS -CMCF CORRELATION

Scheduled Maintenance Tasks

Scheduled maintenance task messages relate to certification maintenance requirement items (CMR) or maintenance review board (MRB) items with time exposure limits.
These messages relate to those that show on the maintenance task maintenance page on the MFD.
These messages are available in the maintenance planning function as:
*
Inbound scheduled maintenance tasks (from maintenance planning menu)

*
Existing scheduled maintenance tasks (from maintenance planning menu).

One or more correlated maintenance messages cause a scheduled maintenance task. There is no requirement to check these messages prior to flight.
Maintenance Memos

Maintenance memos (MO) are a special category of CMCS messages. The purpose of these messages is to report failures in fault tolerant parts of systems. If another failure in that system occurs, it may affect function of the system. They let maintenance organizations plan appropriate actions before a system or component becomes not airworthy.
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These messages are available in the maintenance planning function as:
*
Inbound maintenance memos (from maintenance planning menu)

*
Existing maintenance memos (from maintenance planning menu).

One or more correlated maintenance messages cause a maintenance memo. There is no requirement to check these messages prior to flight.
Maintenance Message Storage
The CMCF stores maintenance messages differently for the different flight phases. This is called flight phase screening. If the maintenance message occurred during a storable flight phase, it is kept in static random access memory (SRAM). The maintenance messages may show on one of these:
*
Inbound flight deck effects

*
Present leg faults

*
Fault history

*
Inbound scheduled maintenance tasks (from maintenance planning menu)

*
Inbound maintenance memos (from maintenance planning menu).

Maintenance messages that do not occur during a storable flight phase are also kept in SRAM. But, these messages are erased when they become not active or unlatched. They show on these:
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CMCS -CMCF CORRELATION

*
Existing flight deck effects

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Existing faults

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Existing scheduled maintenance tasks (from maintenance planning menu)

*
Existing maintenance memos (from maintenance planning menu).

Training Information Point

More than one maintenance message may correlate to an FDE or MO. Find the corrective action for the maintenance message nearest in time to the FDE or MO. If the display does not show the time of the maintenance message, find the corrective action for the maintenance message that shows first below the FDE or MO.
The CPM/COMM SRAM is kept by the hot battery bus. Use the move fault history function from the fault history summary display to move the fault history to diskettes if you are going to disconnect the hot battery bus.
Non-Correlated Maintenance Messages

Non-correlated maintenance messages are those messages that do not relate to a FDE but provide useful diagnostic information. The MAT reports these messages as non-FDE messages.
These messages show in these areas:
*
Present leg faults

*
Existing faults

*
Fault history.

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777 AIRCRAFT MAINTENANCE MANUAL

CMCS -CMCF CORRELATION

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CMCS -CMCF FLIGHT PHASE SCREENING

General

The CMCF uses the flight phase to make a decision about where to store maintenance messages and where to show them on the MAT. This is called flight phase screening.
Flight phase screening prevents the CMCF from storing nuisance or false maintenance messages. Every maintenance message is storable during some flight phases.
Maintenance Message Correlation

The CMCF receives active or latched fault data and changes it to a maintenance message. The CMCF may correlate a maintenance message to one or more of these flight deck effects (FDEs):
　
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