Author Topic: LeCroy X-Stream Calibration Data and Storage  (Read 2376 times)

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Offline ollopa

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LeCroy X-Stream Calibration Data and Storage
« on: July 18, 2018, 03:30:20 am »
This thread will be about X-Stream cal data and who knows, maybe one day we'll be able to do our own poor-man's calibration of repaired equipment  ;)   But not quite yet.

My own experiences upgrading my MB and OS, swapping hard drives for SSDs, and playing with X-Stream have given me some new insights to supplement the information already on the forums and maybe clear up some minor incorrect information.  I thought we could concentrate calibration related information here instead of mixing in with one of the repair threads or the MB upgrade thread.

My information comes from the WR6KA and WP7KA series scopes but it should hold up for all X-Stream scopes.  So without further ado, I'll begin my brain-dump:

The Story We Know So Far
LeCroy partitions the hard drive in two from the factory:  The C: partition contains the OS and firmware and the D: partition contains user data including saved waveforms, scrips, masks, setups, and a hidden folder with cal data named Calibration.  The idea is that you can always safely reinstall the OS and firmware without risking the loss of your user data and calibration.

Common knowledge is that you need to preserve this cal data when swapping out the disk or reformatting the drive to reinstall the OS, otherwise you get the message "This unit's factory calibration data has been moved or does not exist !!!  Please contact LeCroy Customer service for re-calibration. The unit will not meet performance specification."

In my experience once you see this message it will keep coming back even if you have restored the cal data and it is loading properly--more on that in a minute.

How to Backup and Restore Cal Data
On a normal instrument, cal data is in a hidden folder at D:\Calibration.  Simply set the Windows folder options to display hidden files and copy/paste it to a flash drive or network share.  Restoration works the same.

The other way to backup and restore is through the user inaccessible service menu under Service->Critical Files Backup.  This will zip up only the essential files under D:\Calibration and put the archive on a floppy or a thumb drive.

Between the two, I prefer to manually copy/paste the folder since it will retain some files that the critical files backup will ignore.

I Knew That Already, Tell Me Something New
You don't have to have a second partition for the cal data but your options are limited.  By default X-Stream will look for a drive letter named "D:" with a volume name of "USERDATA" and use that for the Maui root path, so all of your user data and cal data will be located there.  This could be any partition or disk assigned the letter "D:" with a volume name of "USERDATA".

If a drive D: with volume name of "USERDATA" is not found then the Maui root path falls back to C:\LeCroy\XStream and your calibration data will be expected to be under C:\LeCroy\XStream\Calibration.  So you can keep everything on the C: drive if you desire by simply not having a D: drive.  Just don't leave a flash drive named "USERDATA" connected when you start X-Stream ;)

Cool, but Why Won't That Prompt Go Away?  I Restored and it's Still There!
You see this:

Once you answer yes or no to the prompt, a registry key is set that will cause the prompt to either always appear (even if cal data is restored and found) or never appear (even if cal data goes missing again).  Kill the prompt by deleting the registry key and then it will be able to return again if there's ever a problem with the calibration files going missing.

The key is a DWORD value under HKEY_CURRENT_USER\Software\LeCroy\Maui named ShowCalibrationDataError.  If 1 you will always see the prompt, if 0 you will never see the prompt, and normal operation is for the key to be deleted / not exist.

So I Lost My Original HDD Before I Backed Up, Am I Screwed?
Surprisingly, maybe not.  The bulk of the critical files are *.btd files which appear to be mirrors/overrides of data stored in EEPROMs on the boards.  If the files are missing from disk then they will be re-created from the contents of the EEPROMs.  On my WR6050 and WP7300A the re-created files were exactly the same as the original btd files on disk, and the scary message box on boot stayed away after I deleted the registry key that forces it to show on every boot.

If the cal data is in EEPROM then why is it also on disk?
I can only speculate but one obvious reason is redundancy since EEPROMs aren't immune to data loss.
According to the Boardtest log, the disk version of the cal data is compared with the EEPROM version on startup and any differences are noted in the log.  I don't know which version gets used if there is a discrepancy but my guess is the disk version.

Another way to use two sets of calibration is to store the factory cal in the EEPROM and the field cal on disk.  That would allow for a third-party cal with the option to revert to the factory cal.  I don't see any evidence that this is the intent for X-Stream, however, and the comparison of the two cals at startup would tend to contradict that use-case.  So it appears that the original intent of the disk cals is to mirror the EEPROM cal rather than partially or wholly override it, but I don't know for certain.

Cursory Inspection of the Calibration Files
I'm hoping people with more free time will expand upon this.  I've only glanced at the Calibration folder but it is made up of:
  • Compensation folder
    • Probe compensations?
    • Contains c1 through c4 folders for channel 1 through channel 4, each having text files of coefficients
    • Contains expertsettings.vbs "ConfigurationVBScript for Channel Compensator"
  • *.btd files which mirror EEPROM data on the front end.
    • "btd" stands for Board Test Data
    • Concatenated list of "structures" that are identified by name and located at fixed offsets
      • AAcqBtd*********
      • Serial_Number***
      • DsoSerialNumber*
      • Mst429DelayC****
      • NcoPathCorr*****
      • VCXOControl*****
      • TrigHystLF******
      • TrigPathDiff****
      • TrigPathDiffExt*
      • CalsoftInfo*****
      • CalCacheInfo****
      • AMadTempBtd*****
      • SERIALNUMBER****
      • OfstCurvePoints*
      • GainCurvePoints*
      • ConvCurvePoints*
      • DlayCurvePoints*
      • OpDlCurvePoints*
      • DC_Parms_A_*****
      • DC_Parms_B_*****
      • DC_Parms_C_*****
      • BWDATA1A********
      • BWDATA1B********
      • BWDATA1C********
      • BWDATA1D********
      • BWDATA1E********
      • BWDATA1F********
    • AAcqBTD.btd - Acquisition system cal parameters and DSO (instrument) serial number
    • FeBTDC1.btd through FeBTDC4.btd - Front End cal parameters for channel 1 through channel 4
    • Had440BTDC1.btd through Had440BTDC4.btd - Hybrid ADC cal parameters for channel 1 through channel 4 (All models use Had440 for the file name even though, for example, WR6K's have HAD639's)
  • ScopeInfo.txt - calibration log metadata
    • Date of calibration
    • Calibration software version
    • Instrument model
    • Firmware version at time of calibration
    • Installed options at time of calibration
    • Instrument OS and CPU specs
    • Instrument serial number
  • Trigger threshold.crv - binary file of some sort, not backed up to EEPROM as far as I know
  • CalCache.mdb and/or CalCacheB.mdb
    • MS Access database files that cache calibration data for quick recall
    • Not part of "Critical Files Backup"
    • Password protected, password is LecroyCalibration196
    • Somebody explore and figure out how to interpret the data!  :)

Some of the "Structures" (cal parameters) are missing in both the files and EEPROM of both my scopes.  I've seen this pointed out by another member of the board and I have to conclude that this is not uncommon and not necessarily an error.  The mere absence of some structures does not cause the "factory calibration data missing or moved" prompt and it appears to be a feature of several instruments with clean histories.  Perhaps some calibrations are only performed if the instrument is out of spec without it and ignored if it is within spec.

More to come!
I will post more detailed information about parsing the BTD files and a strange registry setting used to point the Maui root path (but not cal data path) to a read-only partition.
« Last Edit: July 18, 2018, 03:34:58 am by ollopa »
The following users thanked this post: lukier, analogRF, pilotchup, Kirkhaan

Offline pilotchup

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #1 on: October 01, 2018, 08:49:56 am »
Hi Ollopa,

Very good info, I appreciate your time to write this. I have a WRXi and things are mostly similar.
What's weird for me, is that my "Had440BTDC1.btd" is missing (there is only 2, 3, and 4). The mauiLog file says the error that it is missing, then says it read it from eeprom successfully.. yet it never seems to get put on disk - if it even belongs? Weird..

Just got this scope on eBay, learning a lot about it. Its a 64Xi from early 2006. I ordered a new Pentium M 780 CPU and 1G RAM stick, looking for an SSD solution that will work well with only a 44 pin IDE cable (cant do faster ATA / UDMA modes or corruption ensues from no 80 pin cable). I'm also worried about the cooling and PSU of this thing, since it is early 2006 and never had the "service" or whatever lecroy did to improve them - which you can tell because the blue handle is replaced with a black one.

Any other info or knowledge I'm all ears!!

Offline ollopa

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #2 on: October 01, 2018, 09:10:11 am »
Hi pilotchup,

Do you fly or am I just completely misreading your handle?

I'm still learning what I don't know because I only have two models of hardware to experiment on and the rest is from reverse engineering and tricking firmware into believing it's running on hardware I don't have.

In fact recently I learned that some of the later scopes like the 7Zi series may have done away with the EEPROM storage and btd files completely and now store the cal data in plaintext .vbs files.

Are you missing the Had440BTDC2, 3, and 4 files as well or just the C1 file?  Since you mentioned it I noticed that all of them are missing in one of my virtual instruments and a cal backup zip so clearly they are not always being reproduced and may not be used at all on some scope models -- more investigation needs to be done!


Offline pilotchup

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #3 on: October 07, 2018, 04:20:51 am »
Interesting, that information helps! Yes, I am just missing the C1 version of the "Had440BTD" file. I have 2, 3, and 4. What's weird is the log file noting it is missing, and then subsequently reverting to the board's EEPROM.
Yes I am a pilot, just for recreation (general aviation) :)
I am completely new to Lecroy, I'm really liking it. Although I must say, the availability of information is quite less than a lot of other scopes out there. A few people here (including yourself) have been invaluable to learn about this thing!
« Last Edit: October 07, 2018, 09:14:31 pm by pilotchup »

Offline darkstar49

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #4 on: October 11, 2018, 09:21:11 am »
Yes I am a pilot, just for recreation (general aviation) :)

we should start a dedicated forum for (GA) pilots using Lecroy stuff !!   ;-)

Offline ollopa

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #5 on: October 11, 2018, 09:39:22 am »
You too!?

I haven't flown since my daughter was born and she has no idea that I can fly.  It's just about time to dust off my ForeFlight iPad and get current again, then take her down to the airport and give her another something to brag about :D

Now has anyone flown with their LeCroy scopes and can we think of something useful for them to do in the cockpit?  Maybe we could write a matlab script to do some ADSB decoding or get a direct-conversion VHF IQ demodulator and decode VORs   :)

Somebody needs to start a project to make a battery-powered WaveRunner.

Offline Triodes4ever

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #6 on: February 18, 2019, 09:05:45 am »
Hi Ollopa,
Seems you have quite a lot of knowledge in this area, perhaps you're able to shine some light on the (for me big) issue I am confronted with since yesterday:
I have upgraded the PC part of my 6050 (non-A), went to a decent P4 processor, got 2GB of mem, last part of my plan was to go to SSD.
There are 2 physical spindles here, HDD0 and HDD1, the first is the C drive, the second the D drive. On the D drive there doesn't seem to be anything LeCroy related, the C is the system disk so that was cloned onto the SSD (not by myself though,  so unaware of the clone SW).
Decoupled both C and D physically, installed the SSD (with IDE -> SATA convertor pcb) and powered up. This is lightspeed fast now compared to how it was before, fantastic!
BUT: immediately I observed the coloured channel indicator blocks prompting "No Data Available" instead if showing attenuator and offset values. All 4 channels show the same. Initially I was afraid of having lost the caldata, so I dismantled my SSD and SATA construction and went back to the original HDD setup with the two spindles exactly as it was before. But guess what: the problem remains. My channel indicators no longer report the channel settings. This is seriously BAD.
What obscure process has taken place here, and how on earth do I recover from this misery?

Hope you have any idea of what's exactly going on inside the LeCroy dungeons... btw the OS is Win2Kpro

Cheers Leonard (Netherlands)


Offline ollopa

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #7 on: February 18, 2019, 09:10:53 am »
"No Data Available" just means it didn't trigger.  Check your trigger settings and make sure the scope is not stopped.

Did you copy your cal data from the old D: drive?  You need to enable "show hidden files and folders" in Windows to be able to see the hidden folders.

Offline Triodes4ever

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #8 on: February 18, 2019, 08:03:59 pm »
Hi Ollopa,
Thanks for your response, do think however we┬┤re not aligned on this, so let me try to explain.
Directly under the "graticule" there are 4 coloured blocks, each corresponding to a channel (yellow, magenta, blue and green). Within these blocks, Channel sensitivity and offset is supposed to be shown. When the scope is power-cycled, the previously stored values are retained, and displayed. Not with my scope anymore. The 4 blocks just display "no data available" so the attenuator and offset settings are no longer visible.

Then, I did NOT copy anything as of yet. I once booted from my new SSD, I saw this phenomena just described, realized something was wrong or incomplete, powered down and rewired back to the original situation, with both HDD0 and HDD1 connected to the IDE bus. So, booting up, I see drive C: and D: exactly as before I connected the SSD.

So physically, nothing has changed. No HDD content has been touched, deleted or whatever. The problem as indicated is still there though.

The system must have done something weird after I booted from the SSD. It could be (it was a clone from the C-drive only)  there was no calibration data on there, but
would that matter? Directly after it was brought back to the previous situation which has always worked..

Hope it's clearer now..


Offline ollopa

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #9 on: February 18, 2019, 08:41:25 pm »
Pictures might help.

It sounds to me like you're describing this:

Which you will see if the scope hasn't triggered since firmware start.

Offline Converter

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Re: LeCroy X-Stream Calibration Data and Storage
« Reply #10 on: February 23, 2019, 08:02:37 pm »
Leonard, try to check the connection of the cable between the data acquisition board and the system board. In addition, check that all service voltages from the power supply unit reach ACQ board (there are several connectors).
« Last Edit: February 23, 2019, 09:08:16 pm by Converter »

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