Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips?
When I removed the original NVRAM devices and then put in sockets, I plugged the original devices back in just to see if everything worked. Apparently some cal data was lost just desoldering the devices as I got error messages. It really didn't concern me as I intended to completely recal the meter with my local standards anyhow. It was hours before I plugged the original devices back in so they were completely at room temp. My guess was that since the date codes were 1992 and I did this in 2010 the batteries were almost dead after 18 years and just the shock of desoldering caused the end. Bill - Original Message - From: Mark Sims hol...@hotmail.com To: volt-nuts@febo.com Sent: Wednesday, August 20, 2014 7:20 PM Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips? The problem with removing the chip and copying it is the very real chance of glitching the contents in the process. Much better to make a backup copy first. The 32Kx8 NVRAMS are used for system memory and things like storage of user programs and data. Note that the two 32Kx8 devices are form a 16-bit word. The 2kx8 cal ram is only on the high byte of the data bus. MREAD returns memory contents as a signed integer value (-32768..32767) in ASCII. ___ 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. ___ 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.
Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips?
Bill, Thanks for the insight. I always thought that I lost my CALRAM data by trying to read the chip in my programmer while the chip was still warm. What you are saying is that you did not try to read your chip, just unsoldered, installed a socket, plugged it back in and the data was corrupted. Very interesting. I have done this to three 3458A's and only lost the data on one of the units. This further supports the need to be able to read the contents before unsoldering and have that data be able to be used to program a new chip. Thanks for the insight and I would love to try some programs to do that. I only have Windows systems but I have several USB to GPIB adapter choices, PCI to HPIB adapter choices, and RS232 to GPIB adapter choices. Joe -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Bill Gold Sent: Thursday, August 21, 2014 9:33 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips? When I removed the original NVRAM devices and then put in sockets, I plugged the original devices back in just to see if everything worked. Apparently some cal data was lost just desoldering the devices as I got error messages. It really didn't concern me as I intended to completely recal the meter with my local standards anyhow. It was hours before I plugged the original devices back in so they were completely at room temp. My guess was that since the date codes were 1992 and I did this in 2010 the batteries were almost dead after 18 years and just the shock of desoldering caused the end. Bill - Original Message - From: Mark Sims hol...@hotmail.com To: volt-nuts@febo.com Sent: Wednesday, August 20, 2014 7:20 PM Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips? The problem with removing the chip and copying it is the very real chance of glitching the contents in the process. Much better to make a backup copy first. The 32Kx8 NVRAMS are used for system memory and things like storage of user programs and data. Note that the two 32Kx8 devices are form a 16-bit word. The 2kx8 cal ram is only on the high byte of the data bus. MREAD returns memory contents as a signed integer value (-32768..32767) in ASCII. ___ 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. ___ 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. ___ 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.
Re: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips?
John: I have replaced the 3 NVRAM devices in two different 3458A meters. I didn't do anything to the devices other than to install sockets to make future replacements easier when that issue comes up again. I did not program them or anything, just put the blank NVRAMS in and turned on the meters. I did get a lot of error messages at turn on because there were no calibration constants in the devices. But after clearing those messages the meter worked normally, but was way off on all readings which was expected. I was worried that the other limit constants that were in the old NVRAM would be reprogrammed into the new NVRAMS but it was all there just all of the calibration constants were 0 for the most part. Since I have a complete set of necessary calibration equipment that is required to completely recalibrate the 3458A I went through all of the calibration commands with the proper standards hooked up to the meter, CAL 0, CAL 10.000, CAL 10.000E3 and SCAL and whatever else was required. When I got done both meters would power on with no problems or complaints about calibration needed or whatever. My point here is that putting new blank NVRAMS into the meter does not cause a Mem test 1 high error. Of course you must calibrate the entire meter or send it to HP/Agilent/Keysight or a local lab if you don't have the necessary equipment to do the cal. So my guess is that you have a problem on your A5 Outguard Controller board with addressing memory that is NOT being caused by replacing the NVRAMS. Or you have a problem with one of the RAMs on that board or something. Unfortunately HP/Agilent/Keysight did not ever publish a full set of error messages and what they may mean and what to do about them. Good luck. Bill - Original Message - From: John Phillips john.philli...@gmail.com To: Discussion of precise voltage measurement volt-nuts@febo.com Sent: Wednesday, August 20, 2014 1:53 PM Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips? Hi, I have removed my 32k memory chips form my 3458A. Doe anyone have an easy way to connect them to a windows computer. USB would be my preferred connection to a 28 and 24 pin socket. I would like to be able to read and write to the chips to validate the data. I have replace the chips and still get Mem test 1 High on start up. I really do not want to spend close to $3000 for KeySight to fix this. -- *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. ___ 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.
