3458A calibration data backup and restore?

[carl_lab]

I'd like to make a backup of calibration data before new calibration.

I found these commands for reading memory:
        TRIG HOLD
   QFORMAT NUM
   MREAD 393216
   MREAD 393218
   MREAD 393220
   ...
   MREAD 397308
   MREAD 397310

(source: http://www.prc68.com/I/HP3458DVM.shtml )

Is there a "MWRITE" command to restore data?

Any other recommendations?

[plesa]

Check call section on xDevs.
There are multiple ways how to backup calibration data.
https://xdevs.com/fix/hp3458a/#cal

Or you can use  Python script which works with Prologix
https://github.com/bsdphk/pylt/blob/master/hp3458a.py

http://litstation.marketing.agilent.com/litapp/SearchSN.do?method=openExternalSNSearch&prodNum=3458A

[Dr. Frank]

I'd like to make a backup of calibration data before new calibration.


Is there a "MWRITE" command to restore data?

Any other recommendations?

There are several programs, using MREAD command, to read the complete 2kB nvSRAM.

There is no way to write back via MWRITE, as the CAL RAM is HW and SW protected.
PHK from the time-nuts claims to have an assembler program which can do, but he did not publish.

Therefore, the only way is to desolder the SRAM, and write the content with aid of a programmer, maybe to an SRAM with fresh battery.

Frank

[carl_lab]

OK, thank you, both.
Then this is last resort...

I got a calibration error 101 on 4-wire-resistance using a 742A-10k; last calibration value: 10.000432 kOhm.
I typed in  "CAL 10.000432" and the error arrived.
So, what's wrong?

[plesa]

OK, thank you, both.
Then this is last resort...

I got a calibration error 101 on 4-wire-resistance using a 742A-10k; last calibration value: 10.000432 kOhm.
I typed in  "CAL 10.000432" and the error arrived.
So, what's wrong?

Did you performed ACAL OHMS and after that error persist? Or you would like to calibrate 3458A ?

[ManateeMafia]

The meter is expecting an input value in ohms so you should type 10000.xxx as a value. When you put in 10.000xx it was expecting a 10v input.

[carl_lab]

The meter is expecting an input value in ohms so you should type 10000.xxx as a value. When you put in 10.000xx it was expecting a 10v input.

Thank you!
I will check tomorrow...
It works!

Did you performed ACAL OHMS and after that error persist? Or you would like to calibrate 3458A ?

I tried to perform a manual calibration (DCV, Ohm adjustment).

I'm not sure AC adjustment can be done using our Datron 4808 calibrator or better skip AC adjustment.

[bingo600]

There is no way to write back via MWRITE, as the CAL RAM is HW and SW protected.
PHK from the time-nuts claims to have an assembler program which can do, but he did not publish.

Therefore, the only way is to desolder the SRAM, and write the content with aid of a programmer, maybe to an SRAM with fresh battery.

Frank

@Dr. Frank

Have you read line 131 here.
https://github.com/bsdphk/pylt/blob/master/hp3458a.py

PHK offers hints if you really need the function

But afaik it's only for the NON Calram portion

/Bingo

[Dr. Frank]

@Dr. Frank

Have you read line 131 here.
https://github.com/bsdphk/pylt/blob/master/hp3458a.py

PHK offers hints if you really need the function

But afaik it's only for the NON Calram portion

/Bingo

Yes, I know this already. It's definitely about the CALRAM, as clearly described in the text.
And PHK definitely gave me a Danish "No", when I asked for the assembler code.

Frank

PS.: If you refer instead to line 113, yes these BASIC commands exist, including MWRITE, but as explained, this does not work with the CALRAM.