3458A calibration data backup and restore? - Page 1
Forum section: electronics / general

author: carl_lab
author_rank: Frequent Contributor
timestamp: November 22, 2016, 01:57:35 pm
content: I'd like to make a backup of calibration data before new calibration.I found these commands for reading memory:TRIG HOLDQFORMAT NUMMREAD 393216MREAD 393218MREAD 393220...MREAD 397308MREAD 397310(source:http://www.prc68.com/I/HP3458DVM.shtml)Is there a "MWRITE" command to restore data?Any other recommendations?

author: plesa
author_rank: Frequent Contributor
timestamp: November 22, 2016, 03:44:03 pm
content: Check call section on xDevs.There are multiple ways how to backup calibration data.https://xdevs.com/fix/hp3458a/#calOr you can use Python script which works with Prologixhttps://github.com/bsdphk/pylt/blob/master/hp3458a.pyhttp://litstation.marketing.agilent.com/litapp/SearchSN.do?method=openExternalSNSearch&prodNum=3458A

author: Dr. Frank
author_rank: Super Contributor
timestamp: November 22, 2016, 03:54:54 pm
content: Quote from: carl_lab on November 22, 2016, 01:57:35 pmThere 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

author: carl_lab
author_rank: Frequent Contributor
timestamp: November 22, 2016, 04:25:54 pm
content: 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?

author: plesa
author_rank: Frequent Contributor
timestamp: November 22, 2016, 04:41:03 pm
content: Quote from: carl_lab on November 22, 2016, 04:25:54 pmDid you performed ACAL OHMS and after that error persist? Or you would like to calibrate 3458A ?

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: November 22, 2016, 06:20:04 pm
content: 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.

author: carl_lab
author_rank: Frequent Contributor
timestamp: November 22, 2016, 09:04:35 pm
content: Quote from: ManateeMafia on November 22, 2016, 06:20:04 pmThank you!I will check tomorrow...It works!Quote from: plesa on November 22, 2016, 04:41:03 pmI 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.

author: bingo600
author_rank: Super Contributor
timestamp: November 22, 2016, 09:32:45 pm
content: Quote from: Dr. Frank on November 22, 2016, 03:54:54 pm@Dr. FrankHave you read line 131 here.https://github.com/bsdphk/pylt/blob/master/hp3458a.pyPHK offers hints if you really need the functionBut afaik it's only for the NON Calram portion/Bingo

author: Dr. Frank
author_rank: Super Contributor
timestamp: November 23, 2016, 05:36:11 am
content: Quote from: bingo600 on November 22, 2016, 09:32:45 pmYes, 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.FrankPS.: If you refer instead to line113, yes these BASIC commands exist, including MWRITE, but as explained, this does not work with the CALRAM.