Low cost GPIB (IEEE-488)  USB or ethernet adaptors - Page 1
Forum section: electronics / testgear

author: rhb
author_rank: Super Contributor
timestamp: March 29, 2018, 01:53:40 pm
content: I just got an HP 3478A and went looking for a GPIB adaptor only to discover that all the available adaptors cost about $150 which is more than the meter did.I found that Dangerous Prototypes did several iterations of one 4 years ago, but can find little additional information. It does not appear to be offered for sale anywhere. Does anyone know anything about it? I'd have thought it would be a popular product.Are there alternatives to the Prologix and HP-Agilent-Keysight devices?

author: tggzzz
author_rank: Super Contributor
timestamp: March 29, 2018, 02:04:41 pm
content: Quote from: rhb on March 29, 2018, 01:53:40 pmThere's a lot of information available onthis very forum! If that doesn't answer your question, let us know what more information you need.

author: rhb
author_rank: Super Contributor
timestamp: March 29, 2018, 02:12:43 pm
content: I used the forum search which appears not to be very good.I shall also be looking more closely at links posted here.

author: TiN
author_rank: Super Contributor
timestamp: March 29, 2018, 02:33:11 pm
content: I had grim luck with clone of Agilent dongle (with linux-gpib library) and switched all my GPIB rigs to NI USB-GPIB-HS dongles, not having issue since. Some of USB-GPIB-HS dongles go under 150$ on bay from time to time, well worth the trouble and days not wasted on troubleshooting communication issues.

author: Tony_G
author_rank: Super Contributor
timestamp: March 29, 2018, 03:01:04 pm
content: You need to answer the question "Will I need access to VISA libraries?" first as that will tell you if you need a HPAK/NI adapter or not. If using applications, like labView, that expect the APIs to work is important then you just need to find the cheapest HPAK/NI adapter you can - I've used 82357B clones from eBay, an old Agilent E5810A, National Instruments GPIB-232C, NI GPIB-ENET and my current one a NI GPIB-ENET/100.If you don't need that API layer then the Prologix is a great choice and you can often find cheap ICS ones on eBay.The alternative is to build your own using an Arduino.More info herehttps://www.eevblog.com/forum/testgear/gpib-interface-(ieee488)/TonyG

author: rhb
author_rank: Super Contributor
timestamp: March 29, 2018, 03:32:36 pm
content: I just want very rudimentary command line control. Very strangely when I did a search on the LQ Electronics UG01 all I found was Prologix and Keysight devices (or fakes). When I searched for Prologix devices I found UGsimple and UGplus listings.All want to do is R/W calibration data and log data monitoring some voltage references and resistors using an HP3478A.Is the UGplus a viable choice for this? Intent is to use an MCU to control relays to select the 3478A DUT and some environmental sensors connected to the MCU ADC. To simplify things I will probably use a BeagleBone Black to log to a flash drive.

author: Tony_G
author_rank: Super Contributor
timestamp: March 29, 2018, 03:46:17 pm
content: I've never used the UGPlus but it seems to be able to do the basic control stuff you're after (you might need to modify the code to work with the calibration data though but then again if it is just GPIB command R/Ws most likely not).As for hacking the microcontroller to do other stuff, I think you'd be better off just buying a new one.TonyG

author: rhb
author_rank: Super Contributor
timestamp: March 29, 2018, 03:55:16 pm
content: Quote from: Tony_G on March 29, 2018, 03:46:17 pmHack what? New what? I just want to automate some data acquisition, but don't want to devote a PC to it.

author: Tony_G
author_rank: Super Contributor
timestamp: March 29, 2018, 04:31:54 pm
content: Quote from: rhb on March 29, 2018, 03:32:36 pmI read this as modifying the microcontroller in the GPIB device to do the control as a lot of these low cost adapters simply a GPIB & uC IC.TonyG

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: March 29, 2018, 04:54:10 pm
content: UGPlus is on ebay....did you search there?eBay auction: #https://www.ebay.com/itm/UGPlus-USB-to-GPIB-Controller-Made-in-USA/172082405115?epid=1776118937&hash=item2810e91efb:g:wpYAAOSwRQlXeez3I have one and it works fine with its own PC tool but is not as amenable to programming as, say, the Prologix--which I also have. I could not get their DLLs to work with Java (my choice of programming language). If you are not using a PC then DLLs are not going to work for you, either.Prologix on ebay:eBay auction: #https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xprologix+gpib.TRS0&_nkw=prologix+gpib&_sacat=0

author: rhb
author_rank: Super Contributor
timestamp: March 29, 2018, 05:49:13 pm
content: I did search on eBay. It's just that rather than showing me what I was looking for it would show me something else. That was with google searching ebay.com. The ebay search was even more useless. Instead of "ug01 gpib usb adaptor" I got car parts"BTW The Prologix link you posted failed.I've observed that google has become very hit or miss. A search repeated a few days later will produce different results. So I've got very meticulous about downloading papers and other documentation rather than depend on finding it again. Something in the first two pages may be 6+ pages in the next time.Is the UGPlus interface a GUI? If there's not a command line interface I can't program it via expect.

author: nfmax
author_rank: Super Contributor
timestamp: March 29, 2018, 06:21:54 pm
content: I use a genuine Agilent USB adapter, which I found on eBay from a UK seller before the flood of Chinese counterfeits arrived. I use the Keysight IO libraries - yes I know it's hundreds of megabytes, but frankly disc space is just not an issue these day. It provides a full VISA library, and I use the pyvisa Python package to talk to that. It's easy to create simple scripts, and it also gives me a reason to learn Python properly for more complicated tasks.I've just written a program that takes a data value, calculates and adds the CRC, Manchester-encodes it, creates corresponding waveform data and filters it, then uploads it to my ARB, which I use to FM modulate my RF signal generator. From a keypress I can turn on the RF, send the modulating waveform, and turn the RF off again. This simulates a data message from a mains power monitor (so I can configure a 434 MHz receiver module to receive it). All good clean fun!I have also used the NI USB adapter, NI VISA library, and C# to build a data logging/control application. That worked OK too.I would be inclined to avoid the cheaper adapters that don't come with VISA (or linux-gpib) support.

author: nfmax
author_rank: Super Contributor
timestamp: March 30, 2018, 08:59:40 am
content: @rhb - if all you want to do is to log data, and you don't need to change the measurement type or range* between readings, then it should be possible to do without a GPIB adapter entirely. The 3478A can be put into 'talk only' mode by setting the rear panel DIP-switches appropriately: in this mode, it sends each measurement to the GPIB interface as soon as it is made, without having to be addressed by a bus controller. All you have to do is implement the 3-wire handshake (a trivial state machine) to read successive data bytes from the 8 data lines, and monitor the EOI line to identify the last byte of each reading. You should use the external trigger mode, driving the DVM external trigger input from a microcontroller IO pin, to control the timing of the measurements.Any microcontroller with 5V tolerant IO should be usable, or a suitable level shifter to 3V3 logic. You will need to add pull up resistors, and use or simulate 'open-collector' drivers for the handshake lines.You can extend this to multiple channels, again providing the measurement type is the same for each, by using the voltmeter complete output from the DVM as an input to your microcontroller to tell it it can select the next input channel.*The fixed 'range' can of course be 'autorange' if you don't mind the reduction in measurement speed

author: DC1MC
author_rank: Super Contributor
timestamp: March 30, 2018, 09:18:36 am
content: Quote from: rhb on March 29, 2018, 01:53:40 pmSome while ago I needed a cheap GPIB adapter to send calibration commands to my Solartron 7150.User @Fortran recommended this:http://dalton.ax/gpib/And sold me 2 PCB for a very acceptable price. The components and assembly are cheap and easy and it works. If you just need it for access and no fancy VISA / NI stuff, than I think it's a nice proven adapter.Cheers,DC1MC

author: rhb
author_rank: Super Contributor
timestamp: March 30, 2018, 03:25:04 pm
content: Thanks. I don't have a PIC programmer, which adds some overhead cost. I'm leaning at the moment towards a UGPlus for $40.