my lab

Well, there is WWV :-)

A mix, and that's unavoidable. Older gear that is irreplaceable (because they simply don't make some of the good stuff anymore) inevitably comes with those dreaded HPIB garden hose connections. The logic analyzer and some other gear I rarely use is from the RS232 era. Modern gear like the DSO is USB. And I will absolutely not have HPIB garden hoses here anymore.

So, there is a Prologix HPIB/USB adaptor, an RS232/USB adaptor plus the traditional USB spreader octopus. I raised the equipment rack by 1-1/2" to make all that fit underneath, plus scope probes, chargers, international outlets, a flat vise and whatever else is needed during lab work. Nice thing is, a laptop can now talk to all the important boxes.

I'm so used to GPIB that I'm probably not a good example. It's a great deal nicer than RS232, and given that it's been around so long, I don't have to worry much about OSes not supporting it in detail--unlike USB.

A nice Prologix GPIB-Ethernet is next on my list.

Cheers

Phil Hobbs

GPIB is terrible. The topper happened a long time ago, after I had just laid new carpet. Connector slipped off, the garden hose cable ricocheted, hit my coffee mug which was half full ... *THWACK* ... flew off and crashed onto new carpet. That was the end of GPIB for me. There sure are better busses out there. I used to prefer RS232 but now everything is USB.

If you have to use equipment at clients a lot and its legacy HP stuff the USB version is very practical. Plug it in, hit print on the analyzer, done. But Abdul (the Prologix designer) and I had to iron out a bias problem before it liked HP legacy gear.

Spilling coffee is a criticism of a bus? GPIB can do about 1 MB/s when externally clocked, which is better than good enough for most things I need to do in the lab, and if I tighten the screws I can even keep my coffee and my carpet. ;)

Cheers

Phil Hobbs

Joerg is accident prone... always *PHUT*ing ;-) ...Jim Thompson

Great sound effects, though.

Cheers

Phil Hobbs

I see, I see.

I'm wondering how you control all this on the software side? Tcl?

Ah yes, the equipment rack. I could use one of those. Are you talking about a 19 inch cabinet type thing?

Can you use ribbon cable? I've got a vintage GPIB controller here that works on the Commodore 64. I've never tested it but it comes with a ribbon cable. I suppose you lose stackability and probably some performance with ribbon.

There is no performance to give up. It was a lucky day when GPIB worked at all. ...and often the stackabiity was need *to* get it to work. What a nightmare.

I don't know the prologic stuff but you can get the HP2050 bridge for almost nothing and you're sure all the visa lib and third party software work.

They are so cheap that you can buy as much as you need without even thinking. I now have three of them and all the lab is permanently wired, avoiding Joerg's coffee spill problems. This too allows local GPIB wiring, replacing long GPIB cabling with cat5 between working areas. Could even use small wifi access point instead, but doing mostly very low level analog...

Commodore 64 was pretty slow. You had to work very hard to get full speed out of GPIB with the early PCs and micros. HP had a near monopoly on it in the early days. All the chipsets had their little quirks.

It definitely worked better with the right grade of cables and you could have them custom made to lengths well beyond what the standard allowed and it would still work OK at speed. A lot of older instruments still use it but Ethernet and USB have largely supplanted it now.

Rubbish. In it's day GPIB and IEE488 was a pretty much rock solid workhorse and way ahead of its time. It degraded fairly gracefully because of the handshake mechanism. I never much liked IEEE488.2 tho.

An insulating protector on the back of the stackable plug was wise in a a marginally hostile environment with eg metal swarf or acidic mists. It survived remarkably well even with serious HV and flashovers.

The only thing wrong was that as Joerg mentions the GPIB cable was rigid like garden hose and the heavy connectors were inclined to knock things off the desk if screws came loose. Also that the leverage of a multiply stacked connector was another way people wrecked kit.

ISTR The other amusement was that the pcb IEEE488 connector had unusual pinout ordering which caught out our circuit layout guy.

Regards, Martin Brown

I typically use only one machine at a time, two at the most. But probably they could all run together if I really wanted to.

It's a simple Ikea shelf. Could be "Ivar" or something. Not fancy but low cost and most of all, configurable. I used to have 19" racks but getting older my back isn't so great anymore. The Ikea shelf allows me to gently slide a big analyzer forward and ease it down onto the table for preventive maintenance or repair.

Bullshit. Even HP stuff didn't even work with HP stuff unless the phase of the moon was right. Perhaps if you had one or two instruments it was OK, but try thirty. HPIB was slow crap, when it did work. I'd *never* use it today. Too much of a PITA.

GPIB, but we use GPIB to Ethernet coverter boxes from National Instruments (purchased on Ebay). We have two clusters of GPIB connected equipment, each cluster having its own GPIB to Ethernet converter box. Allows us to deal with equipment far away from my computer. Some modern instruments, we use the Ethernet connection supplied on the back of the instrument.

The nice thing about GPIB, you can write up DOS batch files and submit them through some interface programs that National Instruments has. The NI programs are written for Ethernet communication to their GPIB to Ethernet converter boxes. Makes controlling your equipment really easy.

Longterm, gigabit (and whatever comes next) Ethernet is the only reasonable instrument bus.

John

Sure, unless you need timing coherence between instruments.

Also there's all this nice stuff around that's GPIB & RS232.

I just resurrected a Keithley 410 micro-microammeter (which gives you an idea of its age--the caps inside are from 1960, and it has 8 selenium rectifiers). After replacing the power cord connector with an IEC, it powered up fine. It had almost a nanoamp of offset current when it woke up, but after 3 hours or so it's below 300 fA and still dropping.

No GPIB, though. ;)

Cheers

Phil Hobbs

The IEEE-1588 protocol can sync boxes to within nanoseconds over ethernet

It's also nice when an instrument has a web-page interface, and can be telnet-ed to, without any PC plugin boards or drivers. Or distance limits.

I got a Keithley electrometer for about $150 on ebay. All analog, of course, with a real meter on the front. The lowest ranges are 1e-14 amps and 1e14 ohms full scale.

Ditto!

John

Hey, then you could sit there at Zeitgeist all day long and run it all via a 3G phone :-)

I guess future instruments will be Twitter compatible.

John