Tektronix Arbitrary Function Generators (and Rigol too) - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: November 08, 2014, 05:01:39 pm
content: Anyone have any insight on the Tektronix AFG Series of Arb/Function Generators?One thing that looks attractive about the Tek AFGs is the Arb Express software. I have been thinking about a Rigol DG1062Z or 1032Z (both of which would save some $ over the Teks AFGs - roughly half the price or better), but the Rigol arb creating software just doesn't get very good reviews - although there aren't a lot reviews out there.Anyway, back on the Tek AFGs, the 3000 series appears to be a little long in the tooth - maybe introduced around 2008? It looks like they went through the initial models, then a B version, and now a C version. Anyone know the differences between the three versions? Or how long until Tek is likely to introduce a new generation of AFGs?Tek has an entry model 2021 which is featured as having been built on the experience gained with the 3000 series. It looks like it could be found new or used for about $1300 or less which starts to close the gap on the DG1062Z, and it includes the Arb Express software.Or maybe it makes sense to consider the AFG3021C over the 2021? The 3021 goes to 25MHz for sine waves and has a larger 5.6" vs 3.5" display; the bigger display is nice, and the 3021 will do square waves and pulses at 25 MHz where the 2021 gets to 20MHz on sine waves but only 10MHz on square waves and pulses.* The front panel layout on the 3000 series looks a little better than on the 2000 series - but it might be a minor thing.Then we get to the notion of the 3022C - which would provide a second channel, but it raises the price considerably. Anyone want to make the case that a second channel would be especially useful? (I can believe a 2nd channel is useful since almost everything else from DMMs to scopes to anything that gives you a way to compare and contrast is useful)The big thing for my interest is the ability to make and experiment with arbs. Initially I don't need complex arbs but I'd like an easy way to make various pulse combinations to represent ASCII characters - maybe hundreds to thousands of bytes per string which would be 8-10x as many bits (so memory and to some extent sampling is a consideration). I just want to easily/quickly shape the pulse strings with precise control over frequency, amplitude, duty cycle, etc. If Rigol had something like Arb Express this would be easy. I imagine this could probably be done in Python or some other language but I'd prefer off the shelf PC software.So, between the Rigol 1062/1032 and the Tek 2021, 3021C and 3022C for making arbs - what do you think? Seems like you have to pay 2-3x to get good software - kind of hard to justify.Thanks for any thoughts/advice. EF* I saw specs that say the 3021C goes to 12.5MHz for arbs and half that for arbs in burst mode; the 2021 goes to 10MHz for arbs and half that for arbs in burst mode - so maybe for arbs there isn't much difference between the two models.

author: Omicron
author_rank: Regular Contributor
timestamp: November 08, 2014, 07:55:53 pm
content: If you're in Europe then check out Farnell. They have a promotion going for the AFG2021. Only 575 Euro's at the moment (excl. VAT):http://be.farnell.com/tektronix/afg2021/generator-function-arb-20mhz/dp/2143351

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 08, 2014, 10:01:39 pm
content: Quote from: Electro Fan on November 08, 2014, 05:01:39 pmYes, the Rigol software is pretty poor (I have a DG1062z, and I also wrote a review of that thing including the software some time ago in this forum). I find it slightly better than the software Siglent provides for their AWGs, but it's still a very poor piece of software. Which is a shame as the DG1062z is really good.I also know Arb Express, which in my opinion is still the best free waveform editor out there, and because of Arb Express I am still thinking of getting one of the better Tek AWGs (actual AWG Series not AFG, as the latter are mostly low performance models). Of course the AWG Series is quite expensive, but it would also give me much higher bandwidths and larger sample memory than the Rigol which is a plus.QuoteWell, it seems sample memory size will be an issue for you, and the Tek AFGs all seem to have somewhat small sample memories. I agree that good software is important, but since you already consider rolling your own I'd say you'd be better off with the Rigol.

author: Electro Fan
author_rank: Super Contributor
timestamp: November 09, 2014, 12:23:56 am
content: Wuerstchenhund, I carefully read your review - it was very good - I think it's the definitive Rigol arb review to date. It had me pretty well convinced to look elsewhere for arb software. To clarify, I'd much rather find good off the shelf software than than write software for the arb waveform creation/editing function. Omicron, thanks for the link.Found these:Tektronix Arb Express Software:http://www.tek.com/signal-generator/afg2021-software/arbexpress-waveform-creation-and-editing-sw-v29Keysight (Agilent) BenchLink Software:http://www.keysight.com/main/software.jspx?ckey=2039094&lc=eng&cc=US&nid=-536902257.977229&id=2039094&pageMode=CVBoth can be easily downloaded for trial use. (They both have the ability to load waveforms from scopes, but it looks like maybe only from selected models of their own brand - or maybe there is a way to get them to accept waveforms from other brands through a NI VISA driver? Of the two, the BenchLink software looked more likely to accept waveforms from other manufacturer's scopes.)They both look like they are fairly mature real world pieces of software - would be up for any opinions on how these apps look to you.Thanks, EF

author: w2aew
author_rank: Super Contributor
timestamp: November 09, 2014, 01:46:09 am
content: I use my AFG3000 all of the time. Of course, I work for Tek, but the AFG3000 I own personally. The "C" versions include a newer uP which boots faster, and features an active matrix display which is a vast improvement over the passive matrix displays on the non-C models. The viewing angle was pretty limited on the non-C, but is great on the C models. The ARBExpress software is very handy. If you have a Tek scope, it can help you easily pull a waveform from the scope, modify it if you like, then push it to the ARB waveform memory in the AFG for playback. The AFG2000's lack the modulation and burst features of the 3000, which I've found very handy too. The large display and the larger array of dedicated buttons mean that there are fewer menus to navigate when setting things up. Sure, the basic design has been around a while, but it's ease of use and performance are still very good. Lots of nice features like being able to adjust phase between two channels, as well as being able to have the two channels doing completely different things.In the end, it's a personal choice and you'll have to choose what you'll be most comfortable with in terms of features, ease of use, price, availability, performance, etc.

author: Electro Fan
author_rank: Super Contributor
timestamp: November 09, 2014, 06:23:19 pm
content: Quote from: w2aew on November 09, 2014, 01:46:09 amThanks - Just to confirm, is the ability to pull a waveform from a scope and modify the waveform limited only to Tek scopes? (No way to make other brands interoperable through NI VISA?) On the modulation and burst features are there key functions missing on the AFG2000 relative to those on the AFG3000? The modulation, burst, continuous, and sweep modes look pretty similar in the manuals but maybe I’m missing something.Thanks again, EF (PS, and thanks for your always excellent videos! - Maybe sometime you could do one on the AFG2000/3000 ?)AFG201 Spec Sheet:http://www.tek.com/sites/tek.com/files/media/media/resources/AFG2021_Arbitrary-Function_Generator_Datasheet_75W-28089-0_0.pdfAFG2021 Manual:http://socrates.berkeley.edu/~phylabs/bsc/PDFFiles/ARB_User.pdfAFG3021 Manual:http://www.w12.pwr.wroc.pl/dsp/pliki/AFG3021_user_manual.pdf

author: Electro Fan
author_rank: Super Contributor
timestamp: November 09, 2014, 06:28:13 pm
content: Quote from: Wuerstchenhund on November 08, 2014, 10:01:39 pmWuerstchenhund, any chance you can confirm whether or not it's possible to pull a waveform from a Rigol scope to the DG1062Z and modify it on the DG1062Z? Thanks, EF

author: timb
author_rank: Super Contributor
timestamp: November 09, 2014, 08:25:31 pm
content: I have an AFG2021 and love it. IIRC, Arb Express has the ability to create waveform data from a CVS file, so it would just be s matter of getting a waveform out of your scope in a CSV/TSv format (which most scopes with usb memory stick support can do) then loading it up.I can confirm this tonight if you want.Sent from my Smartphone

author: Electro Fan
author_rank: Super Contributor
timestamp: November 09, 2014, 08:49:53 pm
content: Quote from: timb on November 09, 2014, 08:25:31 pmtimb, Thanks, that would be good but only if you have the time and are up for it. Thx, EF

author: Electro Fan
author_rank: Super Contributor
timestamp: November 09, 2014, 09:29:03 pm
content: Might be out of luck? The Rigol DS2000 manual says:5. CSVSave the waveform data displayed on the screen or of the specified channels in external memory in a single “*.csv” file. You can specify the file name and the saving directory and save the corresponding parameter file (*.txt) under the same directory using the same file name.The recall of CVS and parameter files is not supported.Can anyone with a Rigol 2000 confirm whether a CSV file can be loaded via USB into the scope and then display the waveform from the CSV? Thx

author: alex.forencich
author_rank: Frequent Contributor
timestamp: November 10, 2014, 12:43:31 am
content: Quote from: Electro Fan on November 09, 2014, 06:23:19 pmThe AFG units don't run NI VISA as far as I know. If you need interoperability, a better option might be putting together a small script to run on a control computer to fetch a scope trace and then download it into the arb. If you leverage an instrument abstraction layer (e.g. python ivi) then this can work well for multiple different instruments.

author: Noise Floor
author_rank: Regular Contributor
timestamp: November 10, 2014, 01:57:19 am
content: Quote from: alex.forencich on November 10, 2014, 12:43:31 amQFT. This could be easily accomplished with any hardware you wanted. For the OP, its just a matter of how much effort you want to exert versus paying for more turn key solutions. Sometimes its worth the cost (in $ and loss of flexibility), all depends on your needs and resources.

author: timb
author_rank: Super Contributor
timestamp: November 10, 2014, 10:21:35 am
content: There's a LabView driver for the AFG series. As well as a VISA driver provided by Tek.Sent from my Smartphone

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: November 10, 2014, 12:27:10 pm
content: Quote from: Electro Fan on November 09, 2014, 06:28:13 pmUnfortunately not, as I don't have a Rigol scope, and also no longer have access to one.However if the scope can save a waveform as csv file then you should be able to load it into the DG1000z. Not sure if you can edit it, though, especially as editing over the front panel is limited to 16kpts only.

author: Gertjan
author_rank: Frequent Contributor
timestamp: November 10, 2014, 05:29:45 pm
content: It is possible to pull a waveform from a Rigol scope to the DG1062Z.It is done with a USB connection.According to the manual: "DG1000Z could interconnect with RIGOL oscilloscope which supports USB-TMC seamlessly and rebuilt and output the waveform data collected by the oscilloscope losslessly."I attached the related pages from the DG1032Z manual.I do own a DG1032Z, but unfortunately no Rigol Scope.I'm very happy with my Generator, but I am not using the ARB software.Regards, Gertjan.

author: electronic_eel
author_rank: Regular Contributor
timestamp: November 10, 2014, 07:57:31 pm
content: Quote from: Electro Fan on November 09, 2014, 09:29:03 pmYou can't load a CSVs into the Rigolscopes, that is true. But as far as I understood you, you want to export the CSV from the scope and import it into a arb generator. The arb generators allow importing CSVs, otherwise the arb function would be nearly useless. So that limitation of the scope shouldn't be a problem for you.

author: Electro Fan
author_rank: Super Contributor
timestamp: November 11, 2014, 02:52:27 am
content: Quote from: electronic_eel on November 10, 2014, 07:57:31 pmYes, correct - thank you and thanks to the other posters for talking this through.I think the summary so far is:With a non-Rigol arb generator it is possible (of course) to send the waveform from the generator to the (Rigol) scope. A waveform on the scope can in turn be exported to CSV and then imported into the arb generator, no doubt.Based on Gertjan's post, with a Rigol arb generator it is possible to not only send the waveform from the generator to the (Rigol) scope (of course) but it is also possible to send the waveform directly back to the Rigol arb generator (bypassing the CSV export/import steps).In my case, since I know I can generate rough approximations of the desired ASCII waveforms on a PC - by starting with ASCII text and then sending the text from the PC to the Rigol scope (which displays the text as waveforms) it might make more sense to go with a Rigol arb generator; I could send the text from the PC to the scope and then send the waveforms directly from the scope into the generator where the waveforms could then be modified as needed. This still assumes that either the modifications could be made from the front panel (which is questionable for long ASCII strings), or the Rigol software might be just barely useable enough to make the modifications, or I'm back to writing software (which is my distant 3rd choice; I like and appreciate good software, I just don't write software beyond the very basics).Thus far the choices appear to be either a Rigol DG1032Z or DG1062Z with so-so Rigol software, or the Tektronix 2021 with Arb Express.The Rigol arb gens offer longer arbs, 2 channels, and some other performance and feature advantages including the ability to talk directly to my Rigol scope. The Tek 2021 offers a traditionally thoughtful Tektronix equipment User Interface (almost always a very good thing in my admittedly limited experience) and good software but only 1 channel and no ability to directly import waveforms from a Rigol scope.So, the questions are: 1) how advantageous is it to be able to send waveforms directly from the scope to the generator (without CSV export/import), and 2) is the software going to be off the shelf or self-made. (I downloaded the Rigol software and it probably isn't going to get confused with anything made by Apple or Microsoft. Tektronix Arb Express is pretty nice but with a Tek arb generator it looks like I'd lose the ability to send the waveforms directly from the scope to the arb gen.... decisions, decisions.)Thanks in advance for any more thoughts/suggestions. EF

author: Mark_O
author_rank: Frequent Contributor
timestamp: November 11, 2014, 06:12:40 am
content: Quote from: Electro Fan on November 11, 2014, 02:52:27 amEF, I'm still not completely clear what your actual purpose is for this exercise. I assume, from what I've read, that you'd like to do some sort of noise-susceptibility/immunity testing on RS-232 links, decoding partially corrupted ASCII strings on your Rigol, and seeing how they're interpreted on some serial receiving device(s). So you're spending a lot of time to generate, capture, hand-modify, then retransmit those bit streams.If that's the case, it just seems to me there are easier ways to skin that cat. You could just build a small piece of hardware to stick at the output of a PC serial port, that allows you to inject bursts of noise (or whatever type or duration you like), or trim the signal amplitude (to measure detection thresholds), or gate the signal level to create runt pulses, etc. Or limit the slew-rate to narrow the pulse-width, and so on. Something simple like this (serial in/serial out) shouldn't be hard to build, buta whole lot easier to usethan what you've been proposing. And a lot less expensive to boot.Perhaps you could clarify your requirements/motivations a bit more? If you're just trying to concoct some reason to justify getting an Arb gen, then that's OK too.

author: Electro Fan
author_rank: Super Contributor
timestamp: November 12, 2014, 03:22:20 am
content: Quote from: Mark_O on November 11, 2014, 06:12:40 amMark_O - your always good analytic skills have hit the mark again.I'm just experimenting with (as you say) "immunity testing on RS-232 links" - looking to see at what thresholds for various parameters decoding works or doesn't. And to top it off, you hit the very center of the issue - I am concocting some reason to justify getting an Arb gen.Seriously, you hit it squarely on both notions - but I would like to invest in a tool that lasts awhile before it's superceded by something markedly better for the same price or less. If Rigol could just add some Arb Express quality software to the DG1000Z models it would be an easy decision; as an alternative the Tek 2021 is a thinker.On a related question, anyone out there able to confirm that USB-TMC works not just on the very newest Rigol scopes but on a garden variety DS2072? I saw some threads that indicated USB-TMC might not have been completely dialed-in for a DS072, or vice versa. It would be great to hear from anyone with a DG1000 and a DS2000 who has used USB-TMC to move waveforms from the scope to the generator.Thanks, EF

author: lern01
author_rank: Regular Contributor
timestamp: November 22, 2023, 02:33:47 pm
content: Quote from: w2aew on November 09, 2014, 01:46:09 amI also have an AFG3101, a high-power patch resistor burned, see the picture below, can you tell me how much resistance value? In addition, error is reported in diagnosis and calibration. The error code is diagnosis: 2303, calibration: 1103. Hope you can help. Thank you very much!

author: Mark_O
author_rank: Frequent Contributor
timestamp: November 23, 2023, 08:51:30 am
content: The 2303 code is a Chan 1Output offsetfailure. And the 1103 code is saying there was a Chan 1 Output offsetCal failure. I.e., it can't Calibrate successfully, because it can't adjust that output offset. Due to the resistor. Pretty logical connection.On the fried resistor, I'm sorry I'm unable to help with that. The Tek Service Manual for that instrument does not provide that level of Parts identification. They only discuss Replaceable Parts, which is at the board level. You will need to find an owner of this generator, and hope they will open theirs and take a look inside. All I can see from your Pic is R90 on the PCB, and that may be only part of the ID. I.e., could be R901, or whatever.Or possibly, sincethat is a 2-channel generator, look for the corresponding resistor for Chan 2. Which was NOT blown. You should be able to trace that out on the PCB. And grab the value off that (or measure it, if it is unlabeled).

author: lern01
author_rank: Regular Contributor
timestamp: December 03, 2023, 05:01:28 am
content: Quote from: Mark_O on November 23, 2023, 08:51:30 amCan you provide specific repair suggestions? The output offset should be caused by incorrect DC bias, right? Mainly in which part?The large resistor is the ground resistor of the 5V regulated power supply. It should have a very small resistance, so I short-circuited it directly. It should have no effect on the generator motherboard.I measured several voltages from the CPU motherboard to the generator. When working, +18V -18V 4.2V +5V are basically normal, but -5V is only 4.88V. Is it related to this? no load-4.91V.

author: Mark_O
author_rank: Frequent Contributor
timestamp: December 03, 2023, 01:53:51 pm
content: Quote from: lern01 on December 03, 2023, 05:01:28 amYes. In the resistor that was blown.I made a mistake when reviewing the Service Manual, which describes the 2-channel version of this ArbGen. Then I noticed yours is labeled a a 1-channel unit. However, often these are designed as dual-channel, and then just have 1-channel left unpopulated. As you confirmed with the blank section of the PCB, with the BGA pads. So if you found the matching resistor for Chan 2, it could also be unpopulated as well.I think your best bet on fixing this is to start with the blown resistor, and replace that. (though one might ask what would cause that part to melt down.) Using the KISS principle, find someone who has a working unit, and find the value.I don't have one myself, so I can't help you there. But you might track down an email contact to someone at Tek, who could check and give you that resistor value. I'm guessing they still have the info in their database, even though this instrument was discontinued long ago. But they may be reluctant to take the time to track it down. Time is money, everyone is busy, and no money will be made by getting this unit functional again.

author: lern01
author_rank: Regular Contributor
timestamp: December 04, 2023, 01:49:42 pm
content: Quote from: Mark_O on December 03, 2023, 01:53:51 pmyes，I don't believe they will help with this either. there is no way they would spend time looking for information on equipment that has been discontinued for many years.

author: lern01
author_rank: Regular Contributor
timestamp: December 05, 2023, 01:07:30 pm
content: Fortunately, I got help from my friends at w2aew and learned that it was a MOV, model number TNR5C820K, oxide varistor. Just as I originally suspected, this fault has nothing to do with the resistor.

author: lern01
author_rank: Regular Contributor
timestamp: December 05, 2023, 01:34:05 pm
content: When referring to the maintenance manual, I suspect that one of the prompts in the maintenance tree is wrong. What I understand should be: No, Replace the Generator board. Yes, Replace the Amplifier board. What do you think?