TRAINING MANUAL CFM56-5B FAULT DETECTION & ANNUNCIATION 培训手册 CFM56-5B 故障探测与指示(27)

曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

Example 3 : Line-to-line short circuit.
In this case, the ECU is unable to detect a short circuit as i1 will be the same as i2.
No wraparound fault is generated and there is no change of channel in control.
However, because of the short circuit, the ECU is no longer able to control the torque motor, or solenoid function and a ‘demand/position disagree’ fault is generated.
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION FAULT DETECTION
FAULT DETECTION
& ANNUNCIATION Page 30
Nov 02
  
 
  CFM56-5B TRAINING MANUAL

 

 
NO "SHORT CIRCUIT" DETECTION
NO TORQUE MOTOR CONTROL = "DEMAND / POSITION DISAGREE"
CTC-231-032-00 WRAPAROUND FAULT DETECTION
EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION FAULT DETECTION
FAULT DETECTION
& ANNUNCIATION Page 31 Nov 02
  
 
  CFM56-5B TRAINING MANUAL

 
OUTPUTS
ARINC wraparound test.
Each channel of the ECU has two output ports to interface with the aircraft. ARINC output databus 2 is also used for the Engine Monitoring System for development purposes and aircraft flight test. There are no output differences in the two busses on each channel, unless an ARINC transmitter is faulty, or if databus 2 is in the Engine Monitoring System mode of operation.
In most cases, however, parameter values output by the two separate channels will be slightly different, but within signal tolerance requirements. Data which is specific to a channel, such as fault and maintenance data, may differ from channel to channel.
Each ECU output databus port is driven from a separate transmitter and the databus 1 port is monitored with an individual wraparound test. The ECU verifies for data integrity by looping output databus 1 back to an internal, dedicated input port, within each ECU channel.
Specifically chosen datawords are stored in a source data buffer and continuously transmitted (every 240 msec).
 
The looped-back datawords pass through an ARINC receiver and the datawords received are compared with the corresponding datawords stored in the source data buffer.
The datawords that are looped back are : - VSV Demand
- N1 Command
- N1 Target
- Indicated N1 Actual
- Selected FMV position
The ECU confirms the accuracy of the data, SDI, SM and word parity. If the ARINC output databus 1 transmitter fails the wraparound test, all subsequent
ARINC parameters output on that bus are flagged with an invalid SM.
No wraparound data verification is performed on output databus 2.
 

EFFECTIVITY
ALL CFM56-5B ENGINES FOR A319-A320-A321
CFMI PROPRIETARY INFORMATION FAULT DETECTION
FAULT DETECTION
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：TRAINING MANUAL CFM56-5B FAULT DETECTION & ANNUNCIATION 培训手册 CFM56-5B 故障探测与指示(27)