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Tektronix TDS Scope Field Adjustment Software reverse engineering
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TERRA Operative:
Alrighty, I have got almost all the parts for my PC (enough to have it running DOS and the FAS), including two NI ISA GPIB cards to allow for auto or semi auto calibration.
I have to wrestle with the thing to get the two cards working in the FAS. So far I have one card recognised in the NI diagnostic software, but not in the FAS. I'll have to keep poking away to find the magic combination of settings.

I plan to hook up my SG5030 so the FAS can automatically set the levels and frequencies while I watch to see what's going on. I have a few questions about some instructions (like do I set the signal level to be a specified number of vertical divisions at the sine wave generator amplitude settings, or as displayed on the screen of the scope? etc)

I also got an ebay module that works with Sigrok to use as a 16 channel logic analyzer. I'll make up an adapter so I can sniff the GPIB bus and hopefully see what commands are flying back and forth.
fenugrec:

--- Quote from: TERRA Operative on April 05, 2023, 05:28:54 pm ---So far I have one card recognised in the NI diagnostic software, but not in the FAS
--- End quote ---

As I mentioned somewhere, my understanding is that the resident NI drivers ( that you're loading from autoexec.bat or manually), will interfere with the FAS' low-level access. I could be wrong, but suggest eliminating this possibility.Once basic tests with NI ibdiag etc. succesfully prove that your ISA cards are good, DIP switch or jumpers properly configured etc., you should probably reboot and not load NI's drivers at all.



--- Quote ---(like do I set the signal level to be a specified number of vertical divisions
--- End quote ---
I assume you've seen my video ? For a manual cal, you adjust the amplitude to obtain visually 6 divisions peak-to-peak. Don't forget my comments re RG58 losses at high frequencies too.

I would also suggest running a simple setup first with no automation, maybe just 1 ISA card, to make sure the FAS runs fine and can control the scope.
TERRA Operative:
It's weird as on my previous setup (Dell Precision 410, but only one ISA slot) I had the NI drivers loaded and it all worked fine. This PC is set up identically besides the motherboard and a few other PCI cards and it doesn't work.
I have two ISA slots for the two GPIB cards, but I'm only running one for the tests.
I'll prevent the drivers from loading at boot and see what happens. I bet it's something simple like you say, there can't be too much going on to mess things up.


With the test signal level, if setting the amplitude to a number of on-screen divisions, then how does the automated test do it? And why the call for leveled sinewave generators? I read the instruction the same way (set the sinewave level to 6 on-screen divisions) but then the automated test would need a way to view the screen right? Unless it's doing something with waveform capture and checking that?
fenugrec:

--- Quote from: TERRA Operative on April 05, 2023, 11:27:11 pm ---It's weird as on my previous setup (Dell Precision 410, but only one ISA slot) I had the NI drivers loaded and it all worked fine.
--- End quote ---

Ah, good to know. Still a pretty easy thing to eliminate from the equation. I had freeDOS configured to give me an extra bootmenu entry to load with/without NI drivers so I never really bothered to test the interaction between both, I would just reboot.


--- Quote ---how does the automated test do it? And why the call for leveled sinewave generators?
--- End quote ---

The leveling head of course compensates for cable loss. But I agree it's a silly requirement to be setting the amplitude visually, because if you mess it up, the FAS tells you immediately e.g. "measured 505 MHz, amplitude 6.4 divisions". I would guess the automated test just sets the expected amplitude, measure (either via the scope with a :MEAS command, or it dumps the waveform and does an FFT + amplitude calc), then apply a correction.
pivous:

--- Quote from: TERRA Operative on February 19, 2023, 05:38:07 am ---
FAS asks user to apply test signal to scope -> User applies signal and hits <return> -> FAS directs scope to take measurements -> FAS acquires data and calculates offsets -> FAS loads offsets into scope EEPROM


--- End quote ---

As TERRA operative, mentioned in the first post, could you please confirm if the process of recording the measured correction values into the TDS occurs after every measurement or if it occurs only after the completion of a certain measurement sequence? If it occurs after the sequence, do you happen to know where these sequences start and end? I am wondering if I need to repeat the entire measurement from the beginning in case of an error, or if it is enough to repeat only a part of it. Thank you.
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