R&S rtb2004 Newby segmented memory question - Page 1
Forum section: electronics / testgear

author: alonsojar
author_rank: Contributor
timestamp: November 18, 2022, 05:04:52 pm
content: Hello,I have the opportunity to purchase a refurbished RTB2004. It has the full 300MHz bandwidth and only MSO RTB-B1 option (but not any protocol decoding option that are sold separately at R&S prices).The scope doesn't have any other option active, but my real worry is the lack of segmented memory. The option (RTB-K15) costs more than 1K euro and is not affordable for me.Since I'm not used to modern oscilloscopes, I don't really know how usable will be the scope without such option. I'm checking the manual, but I cannot figure out what is the real impact of this. Of course the segmented memory will store data captured during more samples so you could go forth and back to it searching for events, but does it mean that without that memory I could only analyse the sample that fits on a single scope screen with the resolution used in the capture?I would really appreciate if someone could help me understand this subject (ideally in this particular scope) and evaluate if I should go for the scope or skip it...Thanks!!J. Alonso

author: Fungus
author_rank: Super Contributor
timestamp: November 18, 2022, 05:58:27 pm
content: Quote from: alonsojar on November 18, 2022, 05:04:52 pmNo, that's Siglents that do that, R&S will let youzoom outand see what came before/after.Segmented memory lets you split the memory up into chunks and each chunk will fill up on a separate trigger event.PS: You don't say how much you're going to pay for it...

author: nctnico
author_rank: Super Contributor
timestamp: November 18, 2022, 06:08:32 pm
content: Quote from: alonsojar on November 18, 2022, 05:04:52 pmAs Fungus already wrote: if you set the memory to a fixed length, then the RTB2004 will use the entire memory even if it means some is outside the screen. So you can always see what is beyond the screen to look at previous and next events. History / segmented mode is useful to look at events that are few and far apart.Whether this oscilloscope is a good deal for you depends on your use case. Are you looking at analog signals only or would decoding be useful to you?

author: alonsojar
author_rank: Contributor
timestamp: November 18, 2022, 06:30:22 pm
content: Thank you Fungus and ntcnico, your explanation really helps me.I'm not particularly interested in digital decoding. When I (rarely) try decoding I use an usb logical analyser box connected to my computer and I never missed to mix digital and analog signals. This scope has the digital channels activated, but even a simple protocol like I2C will not be easy to follow (at least for me) in raw without a decoding sw...so probably this part of the scope is quite useless without purchasing some protocols...The price it's offered is 1.6K euros (taxes included). It comes with all probes (included digital channels). I would have preferred to have some other options installed like the ARB generator, but for the activation list price (720 euros) there are good options in the market and with 2 channels and higher specs...Anyway , should it be a good deal in your opinion?

author: tautech
author_rank: Super Contributor
timestamp: November 18, 2022, 06:37:07 pm
content: Quote from: Fungus on November 18, 2022, 05:58:27 pmSome not all, other brands too.

author: nctnico
author_rank: Super Contributor
timestamp: November 18, 2022, 07:54:04 pm
content: Quote from: alonsojar on November 18, 2022, 06:30:22 pmIMHO it is a good deal with the digital probes included AND if you plan to use them. The function generator is a nice to have if it comes in a bundle but otherwise not so interesting.

author: 2N3055
author_rank: Super Contributor
timestamp: November 18, 2022, 08:07:59 pm
content: Quote from: alonsojar on November 18, 2022, 06:30:22 pmIt depends.Segmented memory means you can have 100rds of separate trigger events, capture them over an, say, hour, and then go back and forth replaying them and analysing them. With it RTB2000 has 400-500 MPts available total. Without it all you get is 10 Mpts (20 Mpts when using only 2 ch). Regardless if you use auto mode (all data fits to screen) or fixed memory mode.Without any options and only high bandwidth used scope for 1600€ is not such a good deal. RTB2000 without any options is not much of a scope. All the otherwise nice stuff about it won't be available to you. Siglent SDS1000X-E (or equivalent) literally is more capable in features..You end up with really basic scope with nothing that much cheaper scopes have that have big screen and decent 10bit converter.For 1200€ nowadays you can get fully loaded Siglent SDS2000X+. Heck, you could do a leap of faith and get a new Rigol HDO scope and get 12 bit scope that is analog only if that is all you need, for less money.

author: nctnico
author_rank: Super Contributor
timestamp: November 18, 2022, 08:12:47 pm
content: At the cost of comfort...

author: 2N3055
author_rank: Super Contributor
timestamp: November 18, 2022, 08:13:05 pm
content: Quote from: nctnico on November 18, 2022, 07:54:04 pmWhich part of not going to use it you didn't understand. And he has no decoders, nil, nor segmented memory..In it's current state that scope is practically digital emulation of CRT scope with cursors. And nice big screen.Buying protocols and options at full retail will soon reach price of RTB2K-COM4 full package, but with no warranty..Good price would be 2000-2200€ for a full blown scope. 1600€ for used scope without not even a segmented mode is not much of a deal.

author: 2N3055
author_rank: Super Contributor
timestamp: November 18, 2022, 08:19:19 pm
content: Quote from: nctnico on November 18, 2022, 08:12:47 pmComfort of what? Comfort of not having anything to use.. All of your praise for your R&S RTM3000 are directed at all of the stuff he won't have..He basically buys a screen, ON/OFF switch, few buttons and 4 squiggly lines on a screen. And none of the advanced features. On R&S everything is locked in options. Even Keysight gives segmented memory, and basic decodes for free these days..

author: alonsojar
author_rank: Contributor
timestamp: November 18, 2022, 09:12:53 pm
content: Yeah, 2200 for a full unlocked one looks a good deal, this was my initial idea no matter if initially I plan to use other features the scope can provide (arb, decoders, segmented memory, bode plot etc) or even I know how to use them, but these look hard to find in EU nowadays... Probably I will skip this one and wait for a better opportunity.At least I now know what the h... segmented memory is for!! Thank you all guys.J. Alonso

author: 2N3055
author_rank: Super Contributor
timestamp: November 18, 2022, 09:25:54 pm
content: Quote from: alonsojar on November 18, 2022, 09:12:53 pmI would suggest to go to web sites of scope manufacturers (R&S in this case) and find user manual. Browse through it. There are sometimes whitepapers that explain certain features. Why I say that? Because, many of us came from lod CRT scopes, and none of us used before any of advanced stuff that digital scopes brought . But learning new stuff allows you to do things, better, faster or you could do things you never could do before.

author: Martin72
author_rank: Super Contributor
timestamp: November 18, 2022, 09:47:31 pm
content: Quote from: 2N3055 on November 18, 2022, 08:19:19 pmLooking for it at batronix - Damn, you´re right, this scope comes with "nothing"....Wasn´t aware about it, because it´s unknown from other brands or from brands I usually buy.

author: pdenisowski
author_rank: Super Contributor
timestamp: November 19, 2022, 01:09:46 am
content: I made a short (10 minute) video explaining what segmented memory is and how to configure it on the RTB2000. Hope it helps!

author: 2N3055
author_rank: Super Contributor
timestamp: November 19, 2022, 07:28:32 am
content: Quote from: pdenisowski on November 19, 2022, 01:09:46 amNice video, nicely explained.

author: alonsojar
author_rank: Contributor
timestamp: November 19, 2022, 07:20:13 pm
content: Thanks pdenisowski, the video is very clear showing the advantages of segmented memory managing triggering to catch singular events in long time captures.This is convincing me to continue searching a more complete rtb2k scope with this and others features unlocked. At the end I know I'll be frustrated knowing there are many options inside the box, ... but not for me

author: thikone
author_rank: Contributor
timestamp: November 22, 2022, 01:36:15 pm
content: There is (or there was?) a promotion of RTB2000 scopes. I managed to snatch one fully loaded RTB2K-COM4 for "just" 4.272,00 EUR instead of 8k+ EUR...Was hard to find it on stock though.