Products > Test Equipment
Tektronix TDS754C not communicating over GPIB in unprotected mode
amaschas:
--- Quote from: picburner on November 13, 2024, 07:44:31 am ---An explanation for the lack of response to the *idn? command could be this (taken from the "C" code of the Tektool utility):
--- Code: ---#if 0
/* Test GPIB communication */
/* WARNING - DOES NOT WORK WHEN IN NVRAM-UNPROTECTED MODE ON CERTAIN MODELS! */
ibwrt (Dev, "*IDN?", 5L);
if (ibsta & ERR)
{
GPIBCleanup(Dev, "Unable to write to device");
return 1;
}
ibrd (Dev, buf, 101);
if (ibsta & ERR)
{
GPIBCleanup(Dev, "Unable to read data from device");
return 1;
}
#endif
--- End code ---
If your firmware is corrupt you will be warned during boot, there is an integrity check for this.
--- End quote ---
Interesting, I did actually try a few other commands, including the memory read and write commands requires to backup the firmware or set options and the scope didn't respond, but it's notable that there is a precedent for the scope not responding to certain commands when unlocked. I guess the big question I still have is: what determines the behavior of the scope in unlocked mode? Is it a firmware thing, or is there a bootloader stored somewhere else entirely?
Another interesting bit of information, my scope comes with the 5.3e firmware version, which is the latest version of the firmware for the 754C and is apparently rarely found on this model of scope.
picburner:
According to this document the latest firmware release for a 754C would be the 5.11
But maybe it depends on the hardware version....
amaschas:
--- Quote from: picburner on November 13, 2024, 05:49:13 pm ---According to this document the latest firmware release for a 754C would be the 5.11
But maybe it depends on the hardware version....
--- End quote ---
Oh that's good to know, I was relying on this page: https://w140.com/tekwiki/wiki/TDS754. Maybe a firmware upgrade is in order?
--- Quote from: TERRA Operative on November 13, 2024, 03:17:51 pm ---If you need clean firmware dumps from the NVRAMs, I can probably sort something from one of my spare scopes and send through the files.
--- End quote ---
That would be super useful, thank you! Do you happen to know what version(s) of the firmware you have?
TERRA Operative:
I have a big collection of various firmware, including v5.3e (but not the NVSRAM that holds user data strangely. I do have plans to rip the data from all the chips as I sell these scopes off, to complete my library though) ripped using the Tektools to dump via GPIB.
So, I should have an actual scope here for real that I can dump the both the Firmware and NVSRAM directly from the chips themselves without much problems.
Also regarding a bootloader, there is a UV EPROM chip with a sticker on top on the Processor board. AFAIK, that contains the bootloader. I have found them to be as reliable as UV EPROM chips tend to be. That is to say, I've never had an issue with one before.
If you can tell me the part number on the sticker of your EPROM, I can see if I have one here to rip (or even pull from a spare parts board if I have one of the correct type..)
amaschas:
--- Quote from: TERRA Operative on November 13, 2024, 10:22:56 pm ---I have a big collection of various firmware, including v5.3e (but not the NVSRAM that holds user data strangely. I do have plans to rip the data from all the chips as I sell these scopes off, to complete my library though) ripped using the Tektools to dump via GPIB.
So, I should have an actual scope here for real that I can dump the both the Firmware and NVSRAM directly from the chips themselves without much problems.
Also regarding a bootloader, there is a UV EPROM chip with a sticker on top on the Processor board. AFAIK, that contains the bootloader. I have found them to be as reliable as UV EPROM chips tend to be. That is to say, I've never had an issue with one before.
If you can tell me the part number on the sticker of your EPROM, I can see if I have one here to rip (or even pull from a spare parts board if I have one of the correct type..)
--- End quote ---
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.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version