[time-nuts] Prologix GPIB-USB vs. GPIB-LAN vs. NI was: AW: Prologix GPIB-USB vs. GPIB-LAN

[Robert Darlington]

You can *probably* replace the EEPROM with an FRAM chip (or even a free
sample of an FRAM chip) to get around the wear issues.  I haven't opened my
unit, but this is a serious issue as I'm gearing up to write software to
make a "poor man's" network analyzer using a frequency synthesizer and a
volt meter, switching between them pretty much as fast as possible.  Maybe
I'll just use that NI card ;-)

-Bob

On Mon, Jul 6, 2009 at 11:07 AM, Samuel D. [x86/CPC] <sam at canardpc.com>wrote:

> Damn, that's a big flaw.
>
> The software I'm working on send three "++addr" commands per second.
>
> Only 4 days @24h/day to reach the limit :-/
>
>
> -----Message d'origine-----
> De : time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] De la
> part de Mark Sims
> Envoyé : lundi 6 juillet 2009 18:54
> À : time-nuts at febo.com
> Objet : [time-nuts] Prologix GPIB-USB vs. GPIB-LAN vs. NI was: AW: Prologix
> GPIB-USB vs. GPIB-LAN
>
>
> The Prologix adapter has a ++addr command for changing the GPIB address.
> You can select different instruments that way.
>
> Unfortunately, the version I looked seems to have a potentially fatal flaw.
> When you change the ++addr,  the device writes the internal microprocessor
> EEPROM.  The EEPROM is speced a 1 million write cycles.  If you changed
> instruments at once a second,  in under two weeks the chip could be toast.
> My app could have worn out the chip in under a day...
>
> All this assumes that Prologix did not implement some sort of elaborate
> wear
> leveling scheme in their software,  but I suspect not.  They seem to have
> intended one to set up the device to talk to one instrument then save that
> configuration in the chip.  Dynamically hammering the thing to death with
> address changes was not the intention of the ++addr command.
>
> I wound up implementing  a GPIB controller (with Prologix emulator) with my
> MegaDonkey touch screen LCD controller.  It even included a HPGL/PCL
> plotter
> routine to draw instrument plots on the 160x80 LCD.
>
> ----------------------------------------
>
>
>
>
>
> _________________________________________________________________
> Windows Live™ SkyDrive™: Get 25 GB of free online storage.
> http://windowslive.com/online/skydrive?ocid=TXT_TAGLM_WL_SD_25GB_062009
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>