Author Topic: Tektronix TDS754C not communicating over GPIB in unprotected mode  (Read 2814 times)

0 Members and 1 Guest are viewing this topic.

Offline Tantratron

  • Frequent Contributor
  • **
  • Posts: 598
  • Country: fr
  • Radio DSP Plasma
    • Tantratron
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #25 on: December 03, 2024, 07:20:30 am »
U133 should be the "kernel rom" containing the firmware with basic diagnostic tests and the code to update the Flash memory.
The code contained in U133 is the one that works in "unprotected" mode.
If all the tests are ok it passes the control to the firmware contained in the main Flash memory (5.3e in your case), firmware contained in the two Intel memories side by side, at the top, in your first photo.
U17 I don't know what it is.

The hardware of your scope seems to me to be one of the latest ever produced of this series, nothing to do with my ancient TDS784C.
This is totally correct except the EPROM chip is U1331 but depending on the CPU board (they can be used on C serie or D serie except you need to match the firmware versus the acquisition board C serie or D serie), the Kernel version is different, same for the tek ASIC (chip U1) acting as a 68020 to 68040 translator.
 

Offline Tantratron

  • Frequent Contributor
  • **
  • Posts: 598
  • Country: fr
  • Radio DSP Plasma
    • Tantratron
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #26 on: December 03, 2024, 10:27:04 am »
I couldn't find anything that look very obviously like an EEPROM on the processor board, but took some photos of the board and anything on the board bearing a sticker.
I've looked at your 3 photos from your CPU board compared against my own data base compiled after dealing with more than ten TDS500/700/C/D oscilloscopes.

With C/D serie, there are early model CPU board and late model CPU board so the firmware of these chips (U1331 U17 U1) are not the same. One reason being the DRAM used to be 5V but later sourcing problem so tektronix used 3.3V DRAM => the firmwares had to be changed on 3 chips plus they added an LDO

Your board is legit, namely the 3 chips have respectively correct firmware version 163-0692-00 163-0693-00 and 163-0790-00
« Last Edit: December 04, 2024, 04:58:12 am by Tantratron »
 

Offline Tantratron

  • Frequent Contributor
  • **
  • Posts: 598
  • Country: fr
  • Radio DSP Plasma
    • Tantratron
« Last Edit: December 04, 2024, 05:48:05 am by Tantratron »
 

Offline amaschasTopic starter

  • Regular Contributor
  • *
  • Posts: 125
  • Country: us
  • checking for causal domain sheer
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #28 on: December 06, 2024, 12:30:07 am »
So as a first step, I recommend using National Instruments USB-GPIB (only legacy model built in Hungary) because chinese clone are detected by NI driver and blocked. The prologix had some issues even if it seems to work, personnally I prefer to use real NI equipment which works fine plsu in my case (use of macOS) works super fine.

If you confirm that GPIB is 29 when un-protect mode then you are fine so we will try finding the possible root cause of your problem. It is normal that when in protected mode (address 29), the GPIB query of *IDN? will not work.

Albert

This was the key thing I was missing, thank you so much! I had 3 different GPIB adapters including the NI one, and but the fact that tektool didn't work with the other two I had convinced me that the issue was with the scope, and the fact that the scope didn't respond to *IDN? in unlocked mode seemed to confirm that. I had also tried the options unlock process with the scope in unlocked mode as documented here: https://www.eevblog.com/forum/testgear/hackingupgrading-old-scope-(tds754d)/ but wasn't able to get any response from any of those GPIB commands. But I just tried using tektool with the NI adapter and I was able to connect to the scope and backup the NVRAM, firmware and EEPROM data with the base tektool (not tekfwtool).

I do wonder now why I wasn't able to unlock any of the options. Using the NIVISA software, when I try to send any command like PASSWORD "PITBULL", the interface just hangs for several seconds and just times out.

Thanks for the links to the threads on the different scope models, I will take a look and absorb.
« Last Edit: December 06, 2024, 12:33:17 am by amaschas »
 

Offline TERRA Operative

  • Super Contributor
  • ***
  • Posts: 3172
  • Country: jp
  • Voider of warranties
    • Near Far Media Youtube
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #29 on: December 06, 2024, 03:49:38 am »
Send: PASSWORD PITBULL

Not: PASSWORD "PITBULL"
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 

Offline Tantratron

  • Frequent Contributor
  • **
  • Posts: 598
  • Country: fr
  • Radio DSP Plasma
    • Tantratron
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #30 on: December 06, 2024, 05:03:09 am »
This was the key thing I was missing, thank you so much! I had 3 different GPIB adapters including the NI one, and but the fact that tektool didn't work with the other two I had convinced me that the issue was with the scope, and the fact that the scope didn't respond to *IDN? in unlocked mode seemed to confirm that
Besides the superb NI adapter which works cross-platform (Windows, Linux and macOS), some members reported the tekfwtools to work fine with Agilent 82357B GPIB adapter. I do not have one because the Agilent is not macOS compatible plus the NI model (if made in Hungary) is really awesome so I did purchase few of these in stock.
 

Offline amaschasTopic starter

  • Regular Contributor
  • *
  • Posts: 125
  • Country: us
  • checking for causal domain sheer
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #31 on: December 07, 2024, 11:30:26 pm »
Send: PASSWORD PITBULL

Not: PASSWORD "PITBULL"

This is what I'm trying with the NI adapter with unlock option 1M:

2456139-0

2456143-1

I've tried both the "query" and "write" buttons with the commands, and I've tried it a few times, but 1M remains stubbornly locked. I get that timeout with pretty much any command I try, though of course tektool works so there must be some commands that do function in this mode.

Interesting, I see this little block of code in tektool:

Code: [Select]
/* Only needed in normal running mode, not needed when running in bootloader mode 
   (with scope booted with NVRAM Protection rocker switch in Unprotected position) */
/* send first TEKTRONIX Password fr TDS5xxB/7xxA models to allow memory dump */
  //ibwrt (Dev, "PASSWORD PITBULL", 17L);
ibwrt (Dev, "PASSWORD PITBULL", 16L);

I'm not sure if this just applies to the commented line, or to the password command in general?
« Last Edit: December 07, 2024, 11:35:23 pm by amaschas »
 

Offline TERRA Operative

  • Super Contributor
  • ***
  • Posts: 3172
  • Country: jp
  • Voider of warranties
    • Near Far Media Youtube
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #32 on: December 08, 2024, 06:54:38 am »
I let the scope boot normally, then flip the protection switch and then send the unlock commands.
Then flick the switch back to its normal position and reboot.
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 
The following users thanked this post: amaschas

Offline amaschasTopic starter

  • Regular Contributor
  • *
  • Posts: 125
  • Country: us
  • checking for causal domain sheer
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #33 on: December 09, 2024, 05:33:00 pm »
I let the scope boot normally, then flip the protection switch and then send the unlock commands.
Then flick the switch back to its normal position and reboot.

That did it! specifically used the write command rather than the query command, and when I booted back up 1M was enabled. Thanks so much for all your help!
 

Offline TERRA Operative

  • Super Contributor
  • ***
  • Posts: 3172
  • Country: jp
  • Voider of warranties
    • Near Far Media Youtube
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #34 on: December 10, 2024, 04:05:44 am »
Nice.

Also, you can activate options 2C and 2F without having to add any additional hardware if they are not already acivated.
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 
The following users thanked this post: amaschas

Offline amaschasTopic starter

  • Regular Contributor
  • *
  • Posts: 125
  • Country: us
  • checking for causal domain sheer
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #35 on: December 11, 2024, 05:22:05 am »
Nice.

Also, you can activate options 2C and 2F without having to add any additional hardware if they are not already acivated.

Awesome, just went and did that, thanks for the heads up!

I'm now onto tackling the hardware problems affecting channel 4. I thought the first one was going to be straightforward:

Code: [Select]
diagnostic test failure, digDataFormatDiag1MMem,  ERROR!!in demux 200 ,i= 9 memBaseAdr 0x7380014=  data = ffff8001, expectedData[i] = 0"

I believe that indicates an issue with SRAM IC U210, which I've actually gone ahead and replaced, but still seeing the error. I'm ordered a socket that will allow me to test the SRAM I pulled from the device to see if its still good, and then I'll probably systematically go through the ICs in the demux 200 range until I find a bad one.

The second error I can't find a lot of info about:

Code: [Select]
Internal adjustment range exceeded, 1.0916 => Balance dac #4 (ID #147)"

Though the general advice I've seen around DAC errors is to hit the ICs with a bit of hot air in case there's a solder joint that's gone bad over the years. Not really sure if the balance DAC is distinct from the regular DAC either. But one thing at a time I suppose.

Might also be worth making a new topic about these. I've noticed that its tricky to find information when its buried in a thread about something else entirely, and I'm hoping this odyssey can be useful to others going down this road.
 

Offline Tantratron

  • Frequent Contributor
  • **
  • Posts: 598
  • Country: fr
  • Radio DSP Plasma
    • Tantratron
Re: Tektronix TDS754C not communicating over GPIB in unprotected mode
« Reply #36 on: December 11, 2024, 08:12:35 am »
Might also be worth making a new topic about these. I've noticed that its tricky to find information when its buried in a thread about something else entirely, and I'm hoping this odyssey can be useful to others going down this road.
Yes indeed, best to start a new topic to avoid confusion or mixed cross information... GPIB is one topic, acquisition board DAC and SRAM another topic
You might first check eventually other threads, the issue of DAC/SRAM has been tackled by previous members.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf