GPIB, Whats in it for me - Page 1
Forum section: electronics / beginners

author: jkf1000
author_rank: Regular Contributor
timestamp: August 23, 2016, 10:44:05 pm
content: I have built up a small collection of test gear from various manufacturers. One thing that is common to pretty much all of them is that they have the GPIB connector at the rear. The equipment is all far from new with some dating from the late eighties and I have been researching what the GPIB thing is all about. I have read a little about the National instruments package which from what I can understand offers control and logging options from connected devices but as with most things it comes at a cost, quite a considerable one at £1200. Definately not for the home enthusiast. Also are older machines supported still or is it a generic set of commands used?I have read about third party software packages, but they seem tailored to specific instruments or manufacturers.The PCI GPIB card itself is not a particularly cheap item and then throw in the cost of a few cables it all mounts up. Is there a cheaper/freeware alternative for the software side of things, If I decide to go ahead it will be with an older National Instruments card as it appears to have more software support.Another driving force to the enquiry is the recent purchase of a faulty spectrum analyzer, the display side of things has failed but everything else on it appears fully functional, would GPIB allow me to control/monitor what is going on with the device as part of a diagnostic process.I have done quite a bit of Googling on the subject but I thought I may get more sense from someone on the forum that uses the system..Many thanks in advance. Karl

author: rstofer
author_rank: Super Contributor
timestamp: August 23, 2016, 11:24:56 pm
content: There's probably nothing in it, for you...I have been diddling around with electronics for decades and still don't even have equipment that uses GPIB. My old scope is "what you see is all you get" and I have a new Rigol DS1054Z but I have no interest in the connectivity. One of my DMMs will do data logging and I have never used the feature. When I buy the Rigol AWG and PS, I have no intention of connecting them to a network. What would I possibly do with computer control?If you want to automate a test setup, if you are a QA department, if automated testing is your goal, then GPIB is something of interest and cost won't be an issue.Now, HP hobbyists might want to connect all their equipment to an HP-85 calculator just because they can.

author: edpalmer42
author_rank: Super Contributor
timestamp: August 23, 2016, 11:43:46 pm
content: On the hardware side, check out Prologixhttp://prologix.biz/. They make a GPIB to USB adapter. Also, Keysight 82357B GPIB to USB adapters are common. I don't have one, but apparently most of the ones on ebay are clones but work (?). There's a message thread on them here:https://www.eevblog.com/forum/testgear/flood-of-new-agilent-82357b-gpib-usb-adaptors-on-ebay-the-real-deal/On the software side, Labview Home costs $50 and since you download it, you could have it today!http://store.digilentinc.com/labview-home-bundle/I've used EZGPIB for some general purpose things and Timelab for counters and spectrum analyzers that it supports. There are other packages like PyVISA and pylt for Python. Note that EZGPIB is still available, but no longer supported since the author has passed away.There's a nice GPIB resource listing herehttp://prologix.biz/resources.htmlthat talks about lots of software.GPIB might allow you to check out your spectrum analyzer depending on how much functionality was built-in and how much programming info is available. A few years ago, I bought a really cheap Advantest SA that had a dead display and no keyboard, but it did have GPIB and a VGA output. I used GPIB to send commands and a VGA monitor to look at the results. I sorted out a few other faults and confirmed that the unit was basically working before I spent any money on replacing the missing and dead pieces. It still has 'character' but it's basically working.rstofer makes some good points. Do you want/need to collect data from your equipment? I play with precision oscillators and frequency standards. I need to collect the data so that I can generate graphs to see how well things are functioning. If you want a soft copy of the results from your SA, you probably need some form of data capture. Phase noise graphs? Not very easy to do by hand.It all depends on what kind of toys you play with.Ed

author: bitseeker
author_rank: Super Contributor
timestamp: August 23, 2016, 11:47:38 pm
content: Quote from: jkf1000 on August 23, 2016, 10:44:05 pmSince GPIB isn't "modern" anymore, buying new interfaces, software, etc. often will not be cost effective. It's something you want to get used. Often folks will get a USB- or Ethernet-to-GPIB adapter to connect older GPIB equipment to newer computers that lack ISA or PCI support. Just be aware that there are also counterfeit (branded with NI, Agilent/HP) and clone USB-to-GPIB interface devices out there.QuoteEach device has a command set. Whether a particular software package supports a particular device is something you'd have to check in the specifications. Often, there are drivers to support specific devices, written by the control software provider, the manufacturer of the device, or a third party.QuoteFrom what I've seen, most people seem to write their own code to do what they need with the instruments.QuoteIt depends on the device, but yes, GPIB is a useful way to test the functionality of an instrument especially if there is a problem with the display or controls. An example of this kind of usage can be found in some of The Signal Path videos on YouTube where Shahriar connects a broken device he got on eBay to see if it's alive because the front panel is dead.QuoteAs rstofer points out, GPIB has uses, but not everyone needs it. If you find that you occasionally need to log many values over time, test broken gear, or some other control function that GPIB provides, you can get one interface and one cable rather than connecting everything full time.

author: BradC
author_rank: Super Contributor
timestamp: August 24, 2016, 01:05:32 am
content: A basic subset of GPIB sufficient to talk to the devices is dead easy to implement. I did it on a Parallax propeller with a connector, ribbon cable and some resistors. That was sufficient to configure and pull screen dumps from a Tek 2440 scope, and talk to a HP 3457a meter.It would have been easier to buy an off the shelf adapter, but what would be the fun in that?Certainly, to use all the fruit GPIB can be complex to implement, but on a basic "command - result" basis it's not difficult at all, and even easier if your uController has 3.3v IO.

author: bitseeker
author_rank: Super Contributor
timestamp: August 24, 2016, 04:00:00 am
content: If you have an Arduino Uno handy, you could give this DIY solution a try:http://egirland.blogspot.com/2014/03/arduino-uno-as-usb-to-gpib-controller.html

author: jkf1000
author_rank: Regular Contributor
timestamp: August 24, 2016, 08:36:12 am
content: The Arduino solution looks like an interesting option to look into. A big thankyou to every one for their input as it has certainly helped a lot with my decision making process.If I can use the GPIB as a diagnostic or enquiry tool for fault finding a failed instrument then it seems to be a no brainer, anything that helps the repair process has to be a good thing.Outright control and data logging is not particularly what I am looking for but I can imagine times when it may be useful. (Mainly short term soak testing after repairs)I think I will wait until payday and jump in.. Karl

author: brozier
author_rank: Contributor
timestamp: August 24, 2016, 09:46:12 am
content: If you just want to dump the screen to your PC this HP-GL/2 plotter emulator is worth looking at :-http://www.thegleam.com/ke5fx/He has open source toolkit available as well.Work with the (relatively cheap) Prologix USB-GPIB adaptor.CheersBryan

author: CJay
author_rank: Super Contributor
timestamp: August 24, 2016, 01:56:41 pm
content: Screen dumping, data collection, on some kit it's used to 'fake' functionality, for instance there's a communications tester by HP that only has a 10MHz span (shoot me if I'm using the wrong terminology) but someone wrote a piece of software that automates operation to give a much wider span and display on a PC.You may also find that certain features or extra precision is hidden by the front panel or display of the instrument and it's obtainable via the GPIB connection, some frequency counters give you an extra digit I believe.You can also write your own functions, program test sequences etc. which may not be that useful or may become absolutely indispensable depending what you do with them.In short, YMMV, it's worth investigating but possibly not very useful to you.

author: bitseeker
author_rank: Super Contributor
timestamp: August 24, 2016, 10:06:11 pm
content: Ah, yes. Thanks, CJay. I forgot that some instruments give you access to more resolution, additional functionality, etc. only via GPIB.Regarding the Arduino solution, since it doesn't use driver ICs, just be aware that it won't drive many devices and/or long cables. It should be fine for debugging/repair use.

author: jkf1000
author_rank: Regular Contributor
timestamp: September 01, 2016, 10:40:06 am
content: Well I have bitten the bullet and ordered a used PCI National instruments GPIB card and a couple of HP used cables so I now just need to look into the software side of things. Fingers crossed but if I can get more insight into faulty equipment using it then it is well worth the expense.. Karl

author: RCHRDM
author_rank: Regular Contributor
timestamp: December 31, 2016, 07:35:54 pm
content: This is a little later, but there are some $80-ish Agilent GPIB USB adapters on eBay from China that seem genuine. Mine came in a sealed Agilent box and seems to work fine.See eBay 131361983346Richard

author: Bud
author_rank: Super Contributor
timestamp: December 31, 2016, 07:42:50 pm
content: GPIB does not seem to be going away any time soon. On a Keysight seminar I asked if they plan to obsolete GPIB. "Hell no" was the answer.

author: jkf1000
author_rank: Regular Contributor
timestamp: January 01, 2017, 12:13:35 am
content: I looked into the clone USB units from China but the National instruments PCI card worked out a cheaper option, right place/right time. Also I have found that using a N.I. card, whatever I plug in is found without issue, which may not be the case with a USB converter. I have had a few frustrating hours in the past trying to configure USB to serial devices.It has been a worthwhile investment so far, very useful in diagnosing older test equipment and some items can only be calibrated with the use of the GPIB. I am glad I took the plunge.. Karl

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 19, 2017, 12:37:36 pm
content: Quote from: bitseeker on August 24, 2016, 04:00:00 amThat's a pretty interesting project. I wonder if it could be taken a step further? I have two GPIB devices... a Racal Dana counter and a Keithley DMM... It would be nice to avoid all those expensive thick GPIB wires.... a GPIB to wireless adapter seems feasible?

author: RCHRDM
author_rank: Regular Contributor
timestamp: February 19, 2017, 04:05:13 pm
content: There are some pretty cheap GPIB cables on eBay.

author: JXL
author_rank: Regular Contributor
timestamp: February 19, 2017, 07:21:26 pm
content: Quote from: NivagSwerdna on February 19, 2017, 12:37:36 pmYou can make your GPIB cables with ribbon cable connectors. Custom lenghts, any number of connectors per cable.Similar connector on eBay:http://www.ebay.com/itm/IDC-24-Pin-Male-Centronics-Type-Flat-Ribbon-Cable-FFC-Connector-Adapter-/321483157199?hash=item4ad9e3aecf:g:nbEAAOSwjDZYb9BB

author: mtdoc
author_rank: Super Contributor
timestamp: February 19, 2017, 07:41:17 pm
content: Does anyone have any experience withthese inexpensive USB to GPIB controller cables. I hadn't seen these before on eBay. Looks like a USA made inexpensive clone. Comes with some rudimentary software. For $39 + $7 shipping it might be worth a gamble.

author: Johnny10
author_rank: Frequent Contributor
timestamp: February 19, 2017, 09:09:46 pm
content: I am not sure what is happening in the used NI PCI-GPIB cards market.But if you look around eBay there are many used cards available for 49.00 and up that were over $100 dollars just last year.I picked up a NI- PCI card and now looking for a NI DAQ card.Seems all of these are dropping in price.Mine worked right after installing.Connected my TEktronix 7854, and HP 8903 saw them Immediately.After Clumsily figuring out how to name devices I am very happy with results.

author: joeqsmith
author_rank: Super Contributor
timestamp: February 19, 2017, 10:07:48 pm
content: Quote from: Johnny10 on February 19, 2017, 09:09:46 pmIf ISA boards were being offered on ebay, I wonder if any would sell. PCI is a pretty dead bus now. Seems like there would not be a high demand so the price adjusts. This is why I went from ISA to Ethernet. Of course, they decided not to support it as well. So now I just talk to it direct and don't install the NI-GPIB package.

author: edpalmer42
author_rank: Super Contributor
timestamp: February 19, 2017, 11:13:02 pm
content: Quote from: joeqsmith on February 19, 2017, 10:07:48 pmI was surprised to see that ISA boards sell for as much as $80. Then I realized that if you had a big, old, industrial system that would cost $100K or more to replace, spending $100 for a replacement ISA GPIB board would be a no-brainer. Same would apply for PCI except they often sell for over $100.Ed

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: February 19, 2017, 11:21:17 pm
content: The LQ works for me.I have not done much with it, but it talked to my Keithley out of the box. I just needed to guess which serial port it was mapped to.I have been planning to write some test scripts but have been too busy with other stuff.Randy

author: bitseeker
author_rank: Super Contributor
timestamp: February 20, 2017, 04:25:54 am
content: Quote from: NivagSwerdna on February 19, 2017, 12:37:36 pmYes, definitely feasible especially for a home lab. Probably less reliable in an industrial setting. Depending on how much bandwidth you need, there are many wireless options to explore.

author: bitseeker
author_rank: Super Contributor
timestamp: February 20, 2017, 04:27:28 am
content: Quote from: mtdoc on February 19, 2017, 07:41:17 pmI hadn't seen those before. Doesn't seem too bad. Just be aware that it doesn't have drivers in it, so it won't work with as many devices on the bus or with long cables as well as an interface with drivers.

author: edpalmer42
author_rank: Super Contributor
timestamp: February 20, 2017, 05:01:19 am
content: Quote from: bitseeker on February 20, 2017, 04:27:28 amI haven't worked with these, but I think I read a forum message somewhere (here?) that said they didn't work well at all. I'd spend some quality time with Google before buying one.Ed

author: james_s
author_rank: Super Contributor
timestamp: February 20, 2017, 05:09:41 am
content: I thought GPIB was typically used on production lines to set up instruments for production validation and partially automate testing, it's not something I've ever used myself though, despite having a couple bits of gear that support it.

author: bitseeker
author_rank: Super Contributor
timestamp: February 20, 2017, 05:14:45 am
content: I find it to also be useful when adjusting instruments that have gone out of calibration. It's often much easier to issue commands via GPIB than to fiddle with knobs and buttons.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 20, 2017, 05:43:39 am
content: There are a couple of types of LQ devices, all priced slightly differently. The low end one will drive only one instrument. The high end one can drive the full GPIB spec. I have one of those and it seems fine. The biggest problem is that it is not directly supported by any of the GPIB wrappers out there. It includes a GUI that does a couple of the common tasks (identifying active GPIB addresses) and lets you enter a text script of GPIB commands, so if you code directly in GPIB commands you are home free. It does come with an API, but you have to roll your own SW for instrument control. There is the possibility that it can be brought into one of the existing ecosystems, but I haven't accomplished that yet.The use for GPIB (or ethernet or RS-232 or any of the other control interfaces) is when you are doing repetitive, tedious measurements. Logging a voltage standards performance over time. Or the temperature in the garden. Or the frequency response of an amplifier. Or noise on your favorite ham radio frequency. Or production testing.If you are doing any thing over and over again, and don't find yourself enjoying it, it is time to automate. Cheap older TE uses GPIB.