Any GPIB Experts Out There

[flanneltuba]

Greetings,

I am on a seemingly crazy fools errand to see if I can connect my Tek 2440 digital oscilloscope to a linux laptop using a an Agilent 82357B USB-GPIB adapter. I have gotten things pretty close using linux-gpib with python to the point where at least the laptop recognizes the Agilent adapter. Trouble is I am not able to get any meaningful communication established to the Tek 2440 scope, beyond just getting its GPIB status lights to change occasionally.

I realize I'm fighting several battles simultaneously here. If I had a Windows laptop, I could just run MATLAB with its Instrument Control Module, which I have a use-at-home-able license for through my employer (I'm research faculty at the Univ. of Oregon). Alas, I don't have windows, and don't particularly want it, if it's only for this. There is a version of MATLAB for linux, yes, I am aware. Boy am I aware. I spent 4 or 5 hours banging on it so before I concluded it did not have any drivers for GPIB—only the Windows version has GPIB support Hard earned knowledge.

I do have a CD that came with the Agilent USB-GPIB dongle with all sorts of encouraging looking software, but again, Windows only. Ehhhh....

Anyway, I won't go into too much more detail here unless someone chimes in telling me they have some GPIB expertise that might help me. Otherwise, I'm just wearing out my keyboard and cluttering up the Forum's server with irrelevant noise. Would want to set that precedent! ; )

Thanks,

- Scott

[Chas]

I never had good luck with GPIB using windows and a Tektronics scope. I had Tek on the phone to walk me through it but at that time, 1993, it came down to,having the knowledge to write scripts to get into the 'scope.

As for your Linux O.S. can you get the windows software install inside of WINE and talk to the GPIB adapter? I took an interest in Wine and had it installed in Ubuntu 6.06 (2006) but WINE was not a fully transparent to Windows. It would not work with Autocad. None the less, try your Windows drivers for the GPIB card within WINE. Nothing to loose, install wine and setup the windows environment...

GL

Chas

[Leigh]

Hi Scott,

I wrote several dozen lengthy test programs for HP instruments.
These controlled racks full of sources and metering gear for calibration.

A couple of things to understand about GPIB (IEEE-488)...

#1 - It's STUPID, generally implemented in TTL logic.
Later implementations use programmable logic arrays, no microprocessors until this Millennium.

#2 - Because it's STUPID, you have to give it EXACTLY what it expects. No options.
If it wants 6 digits, you must give it 6 digits. It won't respond to any erroneous format or errors.
Make sure your End-of-Line sequence is correct (i.e. CR, LF, or CR+LF).

#3 - The address you use must match (probably set on DIP switches in the 2440).

#4 - Make sure the 2440 is configured as a Talker (?DIP switch?).
GPIB has a Listener mode in which it says nothing.

#5 - IIRC it only uses upper case.

Note that data reads normally respond with the results of the PREVIOUS measurement.
If you ask for a counter frequency, you get the previous reading, then start a new sequence.
That value will be returned on the NEXT interrogation.

There is a separate GPIB programming manual for the 2440. Do you have it?
Here's the PDF: http://w140.com/tek_2440_programmer_man.pdf" -="window.open(this.href);return false;

- Leigh

[flanneltuba]

Thanks for the suggestions and tips.

I have a feeling that Linux Wine won't work since there would be number of dll's that it needs to have installed to even see the USB dongle, and then others for the GPIB. It's worth a try I suppose though. I'm not overly optimistic.

I'll keep playing with it here.

- Scott

[pehamel]

The right tool for the job (GPIB);
Remember the old pentium box in the attic. This may be the only thing it can do, but it should work with the correct DOS (6.3 was last) or early windows vintage.
Remember - the SAGE computer mainframe system that defended the USA ran with 16 K (yes K) of core memory. (and smart machine-language programmers) a pentium with a good power supply should run your scope easily 24/7 for your project.
Pat

[flanneltuba]

I think you're right, Pat. All of this would be much easier on an actual Windows box. I haven't got one up in the attic—well maybe I do actually—but I just checked with our inventory guy at work, expecting he might say no or point me to a crusty old junker. Instead he directed me to a pile of 5-10 year old intel boxes that were destined for the scrap heap, including a fairly nice Dell with a 2.8GHz i5, gobs of RAM and a something-hundred gig drive... with Windows 7 installed. OK! I just need to wait for them to decommission it and take it off the inventory roster and it's mine.

Saa-weet. Score.

- Scott

[MarkPalmer]

HPIB can be fun if you are adventurous. I'm no expert by any stretch, but I set my HPIB up on an era-correct HP-85 computer with the HPIB interface and related ROM modules. This was easy to do, and I can still program in BASIC which I learned in high school. It serves double duty as I collect vintage computer items, so it’s cool to have something useful to actually do with one. I have also found quite a few programs written by people in the past for various instruments that work well with the system and are fun to mess around with, especially the ones for the HP 8568B spectrum analyzer like automated harmonic distortion measurement and being able to access the FFT features on the analyzer. Programming for my Fluke 8505A multimeters on HPIB allows me to extract quite a bit more from them than what can be done on the instruments locally.

-Mark-

[flanneltuba]

Ok. HPIB you say?! Jeez, I haven't even mastered GPIB!

How is HPIB different or the same as GPIB?

I am looking forward to writing some programs to play around with the GPIB, once I can get basic CPU<->Scope communications established. Linux was a no-go, and sucked a couple dozen hours of my life, but I did become familiar with the basic concepts, even though I never actually got a connection established.

- Scott

[MarkPalmer]

HPIB/GPIB/IEE488- all the same. If history serves me right, Hewlett Packard developed the interface as HPIB, and it became a universally accepted "general purpose" interface bus or GPIB.

-Mark-

[Leigh]

HPIB changed to GPIB when it became generally available.

Some companies did not want to market a product with Hewlett-Packard in the name.

The IEEE later released it as one of their standards, IEEE-488.

- Leigh