MEMS DMRS Test Knowledge Flashcards
What subassembly does the DMRS Eeprom failure point to? What troubleshooting can be done?
DMRS EEprom failure is the interface PBA
- Reprogramming the interface PBA is a trouble shooting method
When looking at the GYRO BITE Failures, what method is best to use?
Ignore everything on the top and use the last self test
The test does not check for the self test BITs
- Tests the BIT is set and then cleared
- Look at the last normal mode fault check (last BIT check at the end of the 8 seconds)
What are RXD files? How can we view the files?
RXD ARE RAW DATA FILES
-WE CANNOT OPEN THEM AND VIEW
-On the test station, the raw data can be converted to a file to read the raw data
oTalk to Kelly
What are characteristics of the power isolation test?
Power isolation tests
- One time test
- boeing wanted dieletric test
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What is different between the results files from the DMRS and AH1000?
Unlike AH1000 the results file is overwritten
What are a few tests done in integration for DMRS?
-Setting up the device configuration file
-A BITE check (contains data from the digital ASIC that the gyro uses to run and uses the FPGA
Is there a difference between the power up sequence in HASS and ATP?
No, the power up sequence in hass is the same in ATP
What is the difference between the AH1000 test files and DMRS test files?
There is only one file that contains PN/SN gyro config file, cal coefficients in DMRS.
What are some characteristics of the self test mode for the DMRS?
Self test mode
-get the gyro started (take 1.5 sec to p-lock)
-1.5 sec starts at self test
-Some cases failures caused the DMRS fail in self test which the DMRS wont go to self test
-It will set a bit (SELF TEST)
-Some cases the failures wont prevent the DMRS to go default mode
What are some characteristics of Default mode?
- Waiting for p-lock
- A can value that sends out rates (same value)
What Lesson goes into depth of start ups for DMRS?
Lesson 3 goes into depth of what start up
What’s a condense version of the power up sequence right when the box is turned on?
- Power is applied
- FPGA reads EEPROM file
- FPGA writes configuration data to Gyro CCA
- Self-Test completes, wait for PLOCK
What does the EEPROM file have?
DMRS Memory
What happens when the FPGA writes configuration data to the Gyro CCA?
FPGA WRITES CONFIGURATION DATA TO GYRO CCA
- Sends data to the analog ASICS
- ASIC sends the data back to the FPGA TO VERIFY THE DATA MATCHES
Where is the EEPROM located on the Interface CCA?
The U1
How can CCA workcell help with EEPROM failures?
They can do probe tests or reprogram with the correct FPGA version.
What is a visual representation of the PLOCK?
Control loop
How is the drive side setup on the PLOCK control loop?
Setup based on the receiving side of the control loop
What is a short summary of how plock is done?
The analog ASIC (control loop or drive side) gives the sensor a kick/push while trying to control it to get it to the right frequency within three attempts. This is done hopefully in 1.5 seconds.
Why are ASICs screened?
They are screened in order to ultimately help the gyro card sensor die to achieve the frequency needed. There is big overdrive from the ASIC at the beginning which makes it hard to control
This is why editing the offset voltage in the analog ASICs and digital ASICS where done
What is one difference between the AC01 and AB01?
AC01 and AB01 have different normal mode transitions time
What is different between each sensor?
Each sensor has their own frequency.
What instrument assembly is used in the INT + HASS test station (js05) to power the DMRS?
The test station (JS05) has an instrument (that is a power supply chassis, 4 power modules for each slot)
What are potential contributors of a DMRS to fail for HASS?
The device being a MOD 0 instead of a MOD 1
Noise in power rails of the IF CCA
Station temperature
What is the ESS drawing requirement for HASS for cold?
Cold dwell is -45 +/- 5 degrees C
What is the ATP test requirement for cold dwelling temperature?
The ATP test requirement is -42 °C to -35 °C
Where in the calibration process are the coefficients determined and used for polynomial correction?
Temperature Calibration
When in the calibration test process are the coefficients for the Gyro Bias Lookup table generated?
The 4-hour temperature sweep at the end of the calibration process.
What is the date format of DMRS tests?
YY-MM-DD
What is ATP temp profile of DMRS?
Cold, Room, Hot
What does the 128 mean in normal status?
Hexadecimal format of Overrange
