Re: TDS694C nvram and tektool

Ragnar S

Hi Gudjon,

(I tried to reply using the Web interface some hours ago, but for some reason that didn’t work. If it later does, I am sorry for the double replies.)

Do I need to flip the nvram protection switch to read the content?
At least I have to boot them with the nvram protection switch flipped on 694C:s with FW v6.3e and v6.4e.
Note that they then get address 29.
Also note that the scope appears more or less dead in this mode, but it responds to GPIB.
I have found versions of tektool that have the address 1 coded in, so maybe on some models or firmware versions they work with the scope booted normally.

I actually just recently modified tekfwtool (and tektool and getcaldata) to work on Linux (and ARM), and published it this morning.
It should be quite possible to make it work on MacOS too, perhaps using macosx_gpib_lib, but I haven’t tried.

You can find it here:

Let me know if you need any assistance, or debug output, or something. I have the setup rigged up in front of me, and can test things if you want to.

In my testing, it was quite sensitive to extra commands. For example, a “*IDN?” in NVRAM unprotected mode screwed up the communication.

Best regards,


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