VALUE FOR FURTHER PROCESSING
HOLD LAST VALID VALUE
FAULT MESSAGE GENERATION "T495 SNSR, J13, ECU"
"T25 SNSR, J11, ECU" "TCC SNSR, J13, ECU"
CTC-231-020-00 DATA VALIDATION AND RANGE TEST
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION FAULT DETECTION
FAULT DETECTION
& ANNUNCIATION Page 7
Nov 02
CFM56-5B TRAINING MANUAL
DIGITAL DATA VALIDATION
If the digital word contains parametric data (parametric values transformed into digital values), the ECU extracts that data and checks the range limits.
ADC data received by the ECU can also be checked against inputs from the engine’s dedicated sensors (P0, PS12, T12). After validation, a weighted average of ADC data and engine sensor values is selected. In
the case where values from both ADC parameters and engine sensors are considered invalid, default values are assigned.
If the digital word contains discrete data (on/off, open/ closed), the ECU determines its validity based on the validity of the word in which it resides. i.e. if the digital word has been passed as ‘valid’, then the ECU considers that the discrete data contained in that word is also valid.
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION FAULT DETECTION
FAULT DETECTION
& ANNUNCIATION Page 8
Nov 02
CFM56-5B TRAINING MANUAL
FEEDBACK LOOPS
RVDT/LVDT.
The RVDT’s and LVDT’s send actuator position information to the ECU and can be considered as a kind of electrical transformer.
They consist of a primary coil (winding) and two
secondary coils, separated by a moveable core.
Resolver.
The resolver is used because, compared to the RVDT’s and LVDT’s, it is more accurate.
The resolver also has two secondary coils, but the moveable core is a rotating primary coil.
Operation.
The excitation voltage for the primary coil is provided by the ECU channel output side and, as the actuator position changes, the moveable core changes the value of the voltage induced into the secondary coils.
The induced voltages from the two secondary coils are provided back to the input side of the ECU channel, where they are subjected to validation tests.
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION
CFM56-5B TRAINING MANUAL
FEEDBACK SIGNALS
CTC-231-022-00 VDT AND RESOLVER
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
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