GPIB controller confusion - Page 1
Forum section: electronics / testgear

author: jpb
author_rank: Super Contributor
timestamp: December 23, 2018, 07:06:04 pm
content: I have a stack of instruments/power supplies that have GPIB connectors so I finally thought it would be a good idea to get a GPIB controller. I've read various posts on this forum and searched ebay and elsewhere and it all seems to be a bit of a nightmare.I bought a NI GPIB-ENET off ebay for £30 + £10 postage which seemed cheap and then I discovered it has a AUI rather than RJ45 ethernet connector so had to spend another £10 on a converter - I'm waiting for them to arrive but having poked around on NI forums it looks like you need a licence to use their driver and it won't run on anything newer than Windows Vista - though hopefully some linux drivers are available.I also bought a couple of GPIB cables which despite being cheap (RS ones on ebay) were still well over £30 for the pair. Most cables seem to be £50+ each even used on ebay except ones from China which probably are a bit dodgy (GPIB seems very sensitive to cables from what has been written on these forums).So I'm thinking I perhaps should spend a bit more on a GPIB-USB controller but the market seems to be swamped with fakes and they are pretty expensive ($200 for a used NI one that looks ok) but again it seems you need a licence for the software driver. Does this mean I can spend a lot of money on hardware and have no means to drive it.I've also looked at PCI cards which are much cheaper - I have a PCI slot in my Dell workstation - but again I am wondering about availability of drivers and whether a licence is needed?I see from a thread on here that you can make your own with EZGPIB (?) software, an Arduino and wiring your own connector but I'd rather buy something (reasonably cheap) if possible.Another alternative is the Prologix one which is quite expensive (£150 plus here in the UK) and from what has been written in some threads it seems that this is not fully compatible with various software libraries.It seems a very good way to waste a lot of money pretty quickly especially when you start buying cables!Some help/clarification would be appreciated - my questions are:1.) Do NI drivers really need a licence and does not having a licence make the hardware useless?2.) Is the Prologix converter any better than the DIY version (other than being much neater) and what do you miss out on if you use it?3.) Should I avoid older PCI card based controllers despite their enticingly low prices?4.) Are the various (probably fake) Agilent GPIB-USB converters ok even if they are fakes? Or should fakes be avoided at all costs?5.) What is the best option for a simple plug in device that will work with modern operating systems (Windows 7 onwards, Linux Centos 7 on) that won't cost a fortune and won't require spending money on software licences?

author: Tony_G
author_rank: Super Contributor
timestamp: December 23, 2018, 07:26:36 pm
content: I picked up a GPIB-ENET to replace a E5810A I had but I ended up giving it away because the drivers wouldn't work on anything later than Win7. I now use a GPIB-ENET/100 and it's been very good for me. I also have one of those fake 82357B USB adapters and it has worked flawlessly as well. The primary reason I went to an NI adapter was that the HPAK ones didn't support enabling devices to become the controller-in-charge. I like the ENET one because I can use it from all my machines, including VMs.In terms of your questions:1. No you don't need a license, you can download them freely from NI.COM2. I have a Prologix that I don't use. I bought it to try and get a equipment initiated print working but it didn't work. The GPIB-ENET/100 works fine in this configuration.3. I don't believe so but it would be up to the driver support if you want something modern.4. The one I have seems perfectly fine and I've seen many posts saying that these work for people so if the price is right I wouldn't hesitate.5. This really depends on what you want to do with the adapter - If you want to write your own stuff then you can pretty much use anything but if you're looking for 3rd party software to work then you need to stay with a mainline controller (Keysight, Agilent, etc) - You're looking for 488.2 or VISA support there really.TonyG

author: Bicurico
author_rank: Super Contributor
timestamp: December 23, 2018, 08:35:52 pm
content: "4.) Are the various (probably fake) Agilent GPIB-USB converters ok even if they are fakes? Or should fakes be avoided at all costs?"I bought my Agilent GPIB USB adapter from eBay. The seller was located in Singapore if I recall it right. It cost around 90 Euro, but I had to pay customs, so at th eend it came to about 140 Euro.The adapter came in a sealed Agilent box with CD and documentation. The adapter is refurbished: looks like new but on very close inspection I could tell it had been used before.The adapter works 100% spot-on and you can download the Keysight IO Suite for free. Take a look at my blog entry, where I discuss the connection to the R&S CMU200/CRTU with my software:https://vma-satellite.blogspot.com/2018/06/remote-control-of-r-cmu200-and-crtu.htmlI would definitely recommend this USB adapter! I don't think it is "fake". I think the box, documentation and seals are fake, but not the device itself. They probably got a huge batch of stock/used units and had new documentation printed. At least that is my guess.Regards,Vitor

author: chronos42
author_rank: Regular Contributor
timestamp: December 23, 2018, 10:08:33 pm
content: I have some of these Agilent fake converters. These converters are fakes for sure, the packages and also the converters.I have four of this, one died after short time of use, the others are still working since more than a year now. Several hp-Agilent instruments (power supplies and ARB generators) are working perfectly, also an older tek scope (TDS 2014), Tektronix open choice software also is working with this converter and the Agilent/Keysight drivers.So all in all I can recommend this adaptor for a lot of tasks.But there is also one big downside: The well known ke5fx plotter emulator is not working with this converter. For this task the Prologix converter is the better tool.

author: jpb
author_rank: Super Contributor
timestamp: December 23, 2018, 10:14:39 pm
content: Thank you everyone for the responses.It makes things clearly. I've probably wasted a bit of money rushing in on the GPIB-ENT but perhaps I can run it on an old Windows XP IBM Thinkpad I have.I'll look into the USB solutions or perhaps a GPIB-ENT/100 if one turns up.

author: Smokey
author_rank: Super Contributor
timestamp: July 04, 2022, 11:03:49 pm
content: bump.Can someone explain why an ancient interface standard that has off the shelf driver ICs still has hardware adapters that cost many hundreds of dollars?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 04, 2022, 11:36:47 pm
content: Simple: they don't!Like, I made my own from the proverbial box of scraps; but the firmware is proprietary, and it's just a shitty serial link. I don't expect it'll run with anything else (though it should run, I think, with a few user-created tools; I just haven't bothered to try yet), and I don't have anything else I have to use it with (i.e. VISA drivers, Excel plugins, etc...), so it's fine with me.Classic adapters, are either needed for compatibility with existing software and hardware (replacing broken components on old installations, where updating hard/software is impossible for a variety of reasons), or because they Just Work(TM) and have the best drivers/compatibility/support.There also just isn't much product movement (assumption), so the price is highly variable. GPIB is old, mostly obsolete; a lot of home lab users just don't need it much, or at all. Most equipment comes with USB/Ethernet these days, with mfg-supplied drivers, or operated directly from a browser.Put another way: how would you solve the apparent problem? If they're as expensive as you perceive, surely there is profit to be made. How much time will it take you to create your own clone? And, can you do so without infringing whatever IP exists? (NI might not appreciate your cloning their USB PID/etc., for example.) Will you sell enough, at the lower price point, to make back your investment?The market seems to agree: no, you won't. Granted, real markets are very, very far from the omniscient optimizers certain people (a LOT of people, actually..) want to think they are. Maybe there is indeed an unseen opportunity here. You can always try!I think a better way to view it would be: to a certain extent, the well known, classic, brand name devices remain expensive, because they are sought after -- whether merely as collectibles (unlikely, but probably a few?!), or for a purpose. Either way, they're moving out of circulation, at least at a given price point, so these are functionally similar outcomes. Meanwhile, for those who are more flexible (tolerant of poorer quality tools, no support), there are myriad cheaper options, including "free". Put another way: the confusion seems to revolve around highly visible, brand-name items; rather than comparing them to themselves, compare to the myriad poorly visible, no-name or even free items/solutions. Which, being poorly visible and numerous, are... hard to see, hence the confusion.Which, to solve that, try searching relevant keywords: clones (especially of moderately-well-known adapters e.g. Prologix); Github for GPIB adapter sources; Tindie, OSH Park, etc. for proprietary or free designs; etc.Examples:OSH Park, GPIBTim

author: artag
author_rank: Super Contributor
timestamp: July 04, 2022, 11:37:38 pm
content: Because the rule for pricing is based on what people will pay, not on what it costs to make.The majority of these adapters are sold to companies who spent thousands on the testgear and thousands more on writing programs to use them, usually custom test programs for their particular job. A few hundred on a well-supported adapter and runtime libraries is nothing.

author: Smokey
author_rank: Super Contributor
timestamp: July 09, 2022, 12:37:54 am
content: Does it even matter which expensive GPIB-USB interface you use? Will Agilent/HP/Keysight stuff refuse to work with an NI adapter?

author: rfclown
author_rank: Frequent Contributor
timestamp: July 09, 2022, 02:05:11 am
content: I've been using GPIB for a long time, and a while back I settled on NI as being the least problematic (with working with anything). I discovered that while working with SBUS cards in Sun Workstations. The HP card worked with HP stuff, but the NI card worked with anything. (before that I was using IOTech GPIB cards in PCs) I presently use GPIB-USB-HS (have one at work and one at home). Anything else seems to be a project in getting it to work with (whatever). I have NI-VISA set as primary, and if some Keysight (Agilent (HP)) thing insists on having Keysight (Agilent(whatever)) IO libraries, that is set as secondary. I paid $200 bucks or so for the things on eBay, and they just work. You can roll your own, or buy cheaper interfaces, but they become a project to making them work with (whatever). I understand wanting to save a buck and wanting to make something work on the cheap, but at some point the time and aggravation isn't worth it.