I do have a ni gpib-usb-hs http://sine.ni.com/nips/cds/view/p/lang/en/nid/201586 I was hoping to remove the chip, read the data with a usb programer and wright the data back into a new chip before installing it. Then do a full calibration. If the 16k chip has the cal vars what do the other 32k chips have? Thanks for the input. I should be able to read to read the data from a good meter with the MREAD and wright it with a programer.
I have been using excl to read program 3458As I will see if I can get MREAD to work there. On Wed, Aug 20, 2014 at 5:33 PM, Mark Sims <hol...@hotmail.com> wrote: > You REALLY don't want to mess with that 24 pin NVRAM chip... it contains > the calibration memory. If you bugger the data in it, you get to spend a > couple of grand getting the meter back into working order. I know a couple > of people that did just that. > > The solution is to first make a backup copy of the memory contents using > the (undocumented) MREAD command over the GPIB bus. Poul-Henning Kamp > figured out how to do it... buy the man a beer... even better a case of > beer... Search the archives for details. > > I just backed up all the memory in my 3 HP3458A's for when the inevitable > BIG BAD DAY comes and the backup batteries go bye-bye. If you happen to > have a NI GPIB-232CV-A (or possibly a Prologix) RS-232 to GPIB converter > and can run a DOS or WIN98 program, I have a program that dumps the memory > chips. It has code for the Prologix in it, but I've only used it with my > a Prologix compatible unit I built... I don't have a real Prologix to test > it with. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > -- *John Phillips* _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.