Empathy List Archives

N

new

Wed, Mar 26, 2014 5:19 PM

The question is... if the 3458 RAMs store the calibration "magic" numbers.... if the ac (main) power is turned off, does it mean the RAM batteries are now under load to preserve the data?

If this is the case, would it be best to leave the unit on a UPS and keep it on 24/7/365? (But... will this kill the display?)

That way, it would never lose the cal magic, right?

If the cal constants are in the RAMs and the RAM batteries go dead, the 3458 needs to go back to Loveland, right?

Does any "RAM" error, HI, LO, etc. mean that it's time to go to Loveland?

Sorry for all the questions, I'm sure they were answered in the past - I'm new here!

Willy, owner of one working and one sick 3458...

The question is... if the 3458 RAMs store the calibration "magic" numbers.... if the ac (main) power is turned off, does it mean the RAM batteries are now under load to preserve the data? If this is the case, would it be best to leave the unit on a UPS and keep it on 24/7/365? (But... will this kill the display?) That way, it would never lose the cal magic, right? If the cal constants are in the RAMs and the RAM batteries go dead, the 3458 needs to go back to Loveland, right? Does any "RAM" error, HI, LO, etc. mean that it's time to go to Loveland? Sorry for all the questions, I'm sure they were answered in the past - I'm new here! Willy, owner of one working and one sick 3458...

PK

Poul-Henning Kamp

Wed, Mar 26, 2014 5:58 PM

In message BC736E8BA2F94F0CB78739D7E04E9D07@KITCHEN, "new" writes:

If the cal constants are in the RAMs and the RAM batteries go dead,
the 3458 needs to go back to Loveland, right?

The CALRAM can trivially be backed up via GPIB.

The backup can either be written into new NVRAM chips using a programmer
or it can with some difficulty be written back via GPIB.

I've explained the details in previous emails to the list (see archives)
and there is software to do the backup in my "Pylt" github project.

In the meantime, keeping it power on means the battery only drain
by their self-discharge.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

In message <BC736E8BA2F94F0CB78739D7E04E9D07@KITCHEN>, "new" writes: >If the cal constants are in the RAMs and the RAM batteries go dead, >the 3458 needs to go back to Loveland, right? The CALRAM can trivially be backed up via GPIB. The backup can either be written into new NVRAM chips using a programmer or it can with some difficulty be written back via GPIB. I've explained the details in previous emails to the list (see archives) and there is software to do the backup in my "Pylt" github project. In the meantime, keeping it power on means the battery only drain by their self-discharge. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

RA

Robert Atkinson

Thu, Mar 27, 2014 12:40 PM

Always best to keep it on. No vacuum fluorescent disply to worry about so it's only the cost of power. The back up battery will last much longer. It may even be less than the shelf life as there will be a very tiny "charge" current due to the reverse leakage of the isolation diode.

Robert G8RPI.

From: Poul-Henning Kamp phk@phk.freebsd.dk
To: Discussion of precise voltage measurement volt-nuts@febo.com; new pitts7@williams-net.com
Sent: Wednesday, 26 March 2014, 17:58
Subject: Re: [volt-nuts] 3458a RAM batteries - longer life if unit is continually powered?

In message BC736E8BA2F94F0CB78739D7E04E9D07@KITCHEN, "new" writes:

If the cal constants are in the RAMs and the RAM batteries go dead,
the 3458 needs to go back to Loveland, right?

The CALRAM can trivially be backed up via GPIB.

The backup can either be written into new NVRAM chips using a programmer
or it can with some difficulty be written back via GPIB.

I've explained the details in previous emails to the list (see archives)
and there is software to do the backup in my "Pylt" github project.

In the meantime, keeping it power on means the battery only drain
by their self-discharge.

--
Poul-Henning Kamp    | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG    | TCP/IP since RFC 956
FreeBSD committer    | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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.

Always best to keep it on. No vacuum fluorescent disply to worry about so it's only the cost of power. The back up battery will last much longer. It may even be less than the shelf life as there will be a very tiny "charge" current due to the reverse leakage of the isolation diode. Robert G8RPI. ________________________________ From: Poul-Henning Kamp <phk@phk.freebsd.dk> To: Discussion of precise voltage measurement <volt-nuts@febo.com>; new <pitts7@williams-net.com> Sent: Wednesday, 26 March 2014, 17:58 Subject: Re: [volt-nuts] 3458a RAM batteries - longer life if unit is continually powered? In message <BC736E8BA2F94F0CB78739D7E04E9D07@KITCHEN>, "new" writes: >If the cal constants are in the RAMs and the RAM batteries go dead, >the 3458 needs to go back to Loveland, right? The CALRAM can trivially be backed up via GPIB. The backup can either be written into new NVRAM chips using a programmer or it can with some difficulty be written back via GPIB. I've explained the details in previous emails to the list (see archives) and there is software to do the backup in my "Pylt" github project. In the meantime, keeping it power on means the battery only drain by their self-discharge. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ 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@lists.febo.com

3458a RAM batteries - longer life if unit is continually powered?